Post on 12-Jan-2016
description
Effect on Tg of Copolymerization blending or plasticization
采用共聚和共混可在聚合物体系中引入第二组分增塑方法可向 polymer 体系中添加低分子化合物利用实验可区分单相两相和多相体系
Homework
One-Phase Systems 单相体系(只有一个 Tg )
Miscible polymer blends random or alternative copolymers and plasticized system
如何预测 Tg (因为 Tg 处于两组分之间)
Fox equation
下限
Linear eguation
上限
Glass-transition temperatures of poly(26-dimethyl-14-phenylene oxide)-blend-polystyrene (PPOPS) blends versus mass fraction of PPO
Two-Phase Systems 两相体系(有两个 Tg )
Immiscible polymer blends as well as their related graft and block copolymers and interpenetrating polymer networks
Each phase will exhibit its own Tg1048766
The intensity of the transition especially in the loss spectra (E)is indicative of the mass fraction of that phase
Dynamic mechanical behavior of polystyrene-block-polybutadiene-polystyrene a function of the styrene-butadiene mole ratio
Effect on Tg of Crystallinity 结晶度的影响
结晶聚合物轻度结晶聚合物
fT mTgT图 晶态和非晶态聚合物的温度形变曲线
温度
形变
12 MM
2M1M
Semicrystalline polymers such as polyethylene or polypropylene or of the nylon types also exhibit glass transitions though only in the amorphous portions of these polymers
The Tg is often increased in temperature by the molecular-motion restricting crystallites
Sometimes Tg appears to be masked especially for high crystalline polymers
Effect on Tg of Pressure 压力的影响
Since an increased pressure causes a decrease in the total volume an increase in Tg is expected based on the prediction of decreased free volume
Kf 为自由体积的等温压缩系数
∆K 为 Tg 上下的压缩系数差 Glass transition versus pressure for various substances
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
One-Phase Systems 单相体系(只有一个 Tg )
Miscible polymer blends random or alternative copolymers and plasticized system
如何预测 Tg (因为 Tg 处于两组分之间)
Fox equation
下限
Linear eguation
上限
Glass-transition temperatures of poly(26-dimethyl-14-phenylene oxide)-blend-polystyrene (PPOPS) blends versus mass fraction of PPO
Two-Phase Systems 两相体系(有两个 Tg )
Immiscible polymer blends as well as their related graft and block copolymers and interpenetrating polymer networks
Each phase will exhibit its own Tg1048766
The intensity of the transition especially in the loss spectra (E)is indicative of the mass fraction of that phase
Dynamic mechanical behavior of polystyrene-block-polybutadiene-polystyrene a function of the styrene-butadiene mole ratio
Effect on Tg of Crystallinity 结晶度的影响
结晶聚合物轻度结晶聚合物
fT mTgT图 晶态和非晶态聚合物的温度形变曲线
温度
形变
12 MM
2M1M
Semicrystalline polymers such as polyethylene or polypropylene or of the nylon types also exhibit glass transitions though only in the amorphous portions of these polymers
The Tg is often increased in temperature by the molecular-motion restricting crystallites
Sometimes Tg appears to be masked especially for high crystalline polymers
Effect on Tg of Pressure 压力的影响
Since an increased pressure causes a decrease in the total volume an increase in Tg is expected based on the prediction of decreased free volume
Kf 为自由体积的等温压缩系数
∆K 为 Tg 上下的压缩系数差 Glass transition versus pressure for various substances
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Two-Phase Systems 两相体系(有两个 Tg )
Immiscible polymer blends as well as their related graft and block copolymers and interpenetrating polymer networks
Each phase will exhibit its own Tg1048766
The intensity of the transition especially in the loss spectra (E)is indicative of the mass fraction of that phase
Dynamic mechanical behavior of polystyrene-block-polybutadiene-polystyrene a function of the styrene-butadiene mole ratio
Effect on Tg of Crystallinity 结晶度的影响
结晶聚合物轻度结晶聚合物
fT mTgT图 晶态和非晶态聚合物的温度形变曲线
温度
形变
12 MM
2M1M
Semicrystalline polymers such as polyethylene or polypropylene or of the nylon types also exhibit glass transitions though only in the amorphous portions of these polymers
The Tg is often increased in temperature by the molecular-motion restricting crystallites
Sometimes Tg appears to be masked especially for high crystalline polymers
Effect on Tg of Pressure 压力的影响
Since an increased pressure causes a decrease in the total volume an increase in Tg is expected based on the prediction of decreased free volume
Kf 为自由体积的等温压缩系数
∆K 为 Tg 上下的压缩系数差 Glass transition versus pressure for various substances
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Effect on Tg of Crystallinity 结晶度的影响
结晶聚合物轻度结晶聚合物
fT mTgT图 晶态和非晶态聚合物的温度形变曲线
温度
形变
12 MM
2M1M
Semicrystalline polymers such as polyethylene or polypropylene or of the nylon types also exhibit glass transitions though only in the amorphous portions of these polymers
The Tg is often increased in temperature by the molecular-motion restricting crystallites
Sometimes Tg appears to be masked especially for high crystalline polymers
Effect on Tg of Pressure 压力的影响
Since an increased pressure causes a decrease in the total volume an increase in Tg is expected based on the prediction of decreased free volume
Kf 为自由体积的等温压缩系数
∆K 为 Tg 上下的压缩系数差 Glass transition versus pressure for various substances
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Semicrystalline polymers such as polyethylene or polypropylene or of the nylon types also exhibit glass transitions though only in the amorphous portions of these polymers
The Tg is often increased in temperature by the molecular-motion restricting crystallites
Sometimes Tg appears to be masked especially for high crystalline polymers
Effect on Tg of Pressure 压力的影响
Since an increased pressure causes a decrease in the total volume an increase in Tg is expected based on the prediction of decreased free volume
Kf 为自由体积的等温压缩系数
∆K 为 Tg 上下的压缩系数差 Glass transition versus pressure for various substances
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Effect on Tg of Pressure 压力的影响
Since an increased pressure causes a decrease in the total volume an increase in Tg is expected based on the prediction of decreased free volume
Kf 为自由体积的等温压缩系数
∆K 为 Tg 上下的压缩系数差 Glass transition versus pressure for various substances
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Pressure coeffcients of the glass transition temperatures selected materials
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
以上结果表明增加压力可导致材料的玻璃化这对工程操作例如模压和挤出十分重要在 Tg ( 105Pa )附近操作可使材料硬化
这样就有玻璃化转变压力的术语另外玻璃化转变分子量玻璃化转变浓度(对于稀溶液和增塑)还有外界条件的影响广义上玻璃化转变具有多维性
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
36 Thermodynamics of Crystallization and Fusion
结晶和熔融热力学
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
一高分子晶体与低分子晶体的熔化过程的比较
TmT
比容
低分子比容与 T关系熔化过程是一级相转变发生在非常窄的温度之内( 02K 左右) 突变
物质从结晶状态转变为液态的过程成为熔融
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Tm
熔限
比容
高结晶 polymer 的比容mdashmdash温度关系 1 边熔化边升温突变不明显 2 存在熔限mdashmdash较宽的熔融温度范围的 3-4K
Dilatometric behavior of polymer melting
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
对许多高聚物精心测量每变化一个温度 eg 升 1 维持恒温直到体积不再变化 (24hr) 后再测比容结果过程十分接近跃变过程在终点处出现明确的转折mdashmdash是热力学的一级相转变
只有程度的差别而无本质的差别
所谓一级相转变熔化过程中体系自由能对温度和压力 P的一阶导数发生不连续变化转变温度与保持平衡的两相的相对数量有关按照热力学的定义这种转变通过做实验可以证明
结晶 polymer 的熔融过程是不是热力学一级相转变
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
熔点晶体全部熔化完了的温度
是由于结晶 聚合物 中含有完善程度不同的晶体的缘故
结晶时随着 T darr ηuarr 分子链活动能力减小 还不及作充分的位置调整 这样各个不同阶段结晶状态同时并存 当熔化不完善的晶体 ( 分子链堆不紧密 ) 将在较低的温度下熔融 而完善的晶体则在较高温度下才能熔融 所以在通常升温条件下便出现较宽的熔融温度范围
结晶 Polymer 边熔融边升温的现象
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
依据在突变时 polymer 的各种物理性质发生变化 密度 折光指数 热容 透明性等
(1) 膨胀计 ------- 比容 -Tm
(2)DTA 利用结晶熔融过程发生的热效应大 的特点测 Tm
(3)DSC 法 测定热效应
二 测定 Tm 的方法
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
经验规则 计算
估计 对称的 polymer Tm=2Tg ( K )
不对称的 polymer Tm=15Tg ( K )
( 因 polymer 的结晶和熔化都是通过链段的运动来实现 )
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Differential scanning calorimetric curve of a semi-crystalline polymer
三 Effect on Tm
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
对于熔化过程
由晶态转变到熔融态 由于熔化过程吸热 ΔHgt0 这是不利于 ΔGlt0 的因素 同时熔化过程链段排列变的无序化 ΔSgtgt0 -TΔS 成了有利于 ΔGlt0 的因素 显然 Tuarr 越有利于熔融的进行
在 Tm 处 晶相与非晶相达到热力学平衡即
对于结晶过程∆ Hlt0 (结晶放热)有利于∆ Glt0 但∆ Slt0 即链段规整排列使熵变小不利于∆ Glt0
可用下列热力学函数关系描述 ΔG=ΔH-TΔSlt0
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
ΔH------ 1 mol 重复单元的熔化热 表示分子或链段离开晶格 所需吸收的热量 与分子间作用力强弱有关
ΔS----- 相应的熔化熵标志着熔融前后分子混乱程度的变化 与分子链的柔顺性有关
当 ΔS 一定时 分子间作用力越大 ΔHm uarr Tmuarr
当 ΔH 一定时 链的柔性越差 ΔSdarr Tm uarr
凡是影响到分子间作用和链的柔顺性的因素都会影响 Tm
这就是我们讨论影响 Tm 因素的核心
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
影响 Tm 的因素1 Effect of Chemical Structure on the Melting Temperature
highly regular structures 规整性1048766
rigid molecules 刚柔性1048766
close packing capability 堆砌性1048766
strong interchain attraction 分子间作用力
High melting points are associated with1048766
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
A Regularity
Polyester
规整性越高熔点越高
Tm
265
220
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
B Flexibility
Polyester
刚性越大熔点越高
50
265
Tm
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
C Interchain force
Polyester
增加高分子或链段之间的相互作用 即在主链或侧基上引入极性基团或氢键 可使 ΔH 增大 Tm uarr作用力越大熔点越高
Tm
170
240
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
聚酰胺(聚氨基酸)的熔点随重复单元碳原子数的增加而降低另外奇数或偶数碳原子影响分子链堆砌的规整性
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
聚脲聚酰胺聚氨酯聚酯 PE 它们熔点趋势如图
14 18 22 260
100
200
300 聚脲
聚酰胺
聚氨酯
线型聚乙烯
聚酯
解释 (1) Tm 的高低顺序 (2) 随着它们的重复单元的增加趋
近与 PE 的熔点 ( 可用生成物质分子间氢键和氢键的密度说明)
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
聚酰胺形成分子间氢键与重复单元中碳原子奇偶数的关系A 偶数的氨基酸 B 奇数的氨基酸 C偶酸奇胺 D偶酸偶胺
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
当主链含有双键时链柔性好 rubber 的 Tm 都很低
NR POM PE PTIF
Tm( ) 28 180 137 327
说明 ΔH 和 ΔS 是从两个方面描述分子链的性质因此不可分割共同其作用单在不同条件下两者的主次作用不同
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
D Packing capability
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
E Melting Point Depression in the presence of impurities杂质存在下的熔点降低
The melting point depression in crystalline substances from the pure state is given by the general equation ( Flory )
a the activity of the crystal (活度)
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
( 1 ) Copolymer X the mole fractionA crstallizable fractionB non-crstallizable fraction(杂质即分子链中非结晶共聚单体的摩尔分数)
XB很小时
共聚破坏了高分子链的规整性使得 Tm 下降
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
Conclusion
无规共聚mdash降低均聚物的 Tm 改善加工性能
嵌段共聚mdash聚合物熔点降低极少改善其弹性( SBS )
交替共聚mdash大幅度降低聚合物的 Tm
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
( 2 ) End group端基
mdashInfluence of molecular weight
M0 - the molecular weight of the end mer
Mn - the number-average molecular weight
该式说明分子量越大 Tm越高分子量无限大时 Tm最高
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
( 3 ) Solvent or Plasticizer 溶剂或增塑剂
V1mdashmdashthe molar volume of the solventVumdashmdashthe molar volume of the polymer repeat unit
υ1mdashmdashthe volume fraction of diluent
Χ1mdashmdashthe Flory solvent interaction parameter
在结晶聚合物中加入少量的增塑剂防老剂或者结晶性高聚物的单体与少量另一种单体无规共聚时 Tm 下降
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
F Crystalline-Amorphous Polymer Blend
The above discussion relates primarily to addition of low-molecular-weight species to a high-molecular-weight polymer When the added species is also polymeric quite different analytical relationships hold because of the reduced entropy of mixing
According to the Flory-Huggins approximation
22
2
10
)1(11
mmm H
R
TT
1mdashthe amorphous polymer 2mdashthe crystalline polymerυ2mdashmdashthe volume fraction mdashmdashthe Flory solvent interaction parameter
Equation describes the melting point depression due to mixing of a crystalline polymer with an amorphous polymer
1
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
The important point is the role played by
If is negative the melting point depressions can be realized
If is positive mixtures of two polymer will be in phase separation
In the case of a crystalline-amorphous polymer blend phase separation would not be expected to result in large melting point depressions
111
Determination of the thermodynamics of polymer blending by melting point depression for poly(vinylidene flouride)-blend-poly(methy methacrylate)
eg PVF crystallizes and it is totally miscible with PMMA In fellow Figure Tm depression of PVF is shown
29501
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip
G Other factors relating to the Melting Point 影响熔点的其他因素
Thickness of the lamellae (晶片厚度 l )Tmdeg-晶片厚度为infin的晶体的熔点σe-表面能∆H-单位体积的熔融热
Crystallization temperature (结晶温度 Tc )
Tc-结晶温度Υ-与结构有关的参数
Pressure (压力 P )
Stress (应力)helliphellip