Post on 31-Dec-2015
STRUCTURE AND MORPHOLOGY OF SEMI CRYSTALLINE LDPE NANO-
POLYMER
Khalefa Al Zenidy
Under supervision ofAssoc. Prof. Dr. M. S. Gaafar
OUTLINES
Abstract. Experimental setup. Results. Conclusion.
ABSTRACT
Low density polyethylene (LDPE) nano-polymers were subjected to a high power ultrasonic irradiation as a polymerization initiator, at different times (0, 5, 10 and 15 minutes). Characterization was performed on the non-irradiated and irradiated LDPE samples by recording the XRD patterns and measuring the low power ultrasonic wave velocities (Longitudinal and Shear) together with density measurements.
EXPERIMENTAL SETUP
RESULTS
5 10 15 20 25 30
0 m
in
5 m
in
10
min
15
min
2 Theta [ ]
Inte
nsi
ty [
A.U
]
(110)
(200)
Fig. 2, X-ray diffraction patterns for LDPE samples at different irradiation times.
RESULTS
0 5 10 157.50
7.52
7.54
7.56
a b
Ultrasonic irradiation time [min]
a, [Å
]
4.98
5.00
5.02
b, [Å
]
Fig. 3, Variation of lattice constants (a & b) for LDPE samples at different irradiation times.
RESULTS
0 5 10 15135
140
145
150
155
L D
Ultrasonic Irradiation time [min]
Cry
stal
lite
size
, L [Å
]
5.180
5.185
5.190
5.195
5.200
5.205
5.210
5.215
5.220
5.225
5.230
Inte
rcha
in d
ista
nce,
D [Å
]
Fig. 4, Variation of the crystallite size and inter-chain distance for LDPE samples at different irradiation times.
RESULTS
Fig. 5, Variation of both (longitudinal and shear) ultrasonic velocities for LDPE samples at different irradiation times.
0 5 10 15
1300
1400
1500
1600
Ul Us
Ultrasonic irradiation time [min]
Long
itudi
nal u
ltras
onic
wav
e ve
loci
ty, U
l [m
/s]
600
650
700
750
800
She
ar U
ltras
onic
wav
e ve
loci
ty, U
s [m
/s]
RESULTS
Fig. 6, Plot of the ultrasonic absorption coefficient and ultrasonic viscosity for LDPE samples at different irradiation
times.
0 5 10 151.2
1.3
1.4
1.5
1.6
us
Ultrasonic irradiation time [min]
Ultr
ason
ic a
bsor
ptio
n co
effic
ient
, [
dB/c
m]
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
Ultr
ason
ic v
isco
sity
, us
[mP
a.s]
RESULTS
Fig. 7. Dependence of Poisson's ratio and cross-link density for LDPE samples at different irradiation times.
0 5 10 15
0.325
0.330
0.335
0.340
0.345
0.350
Nc
Ultrasonic irradiation time [min]
Po
isso
n's
rat
io,
0.40
0.42
0.44
0.46
0.48
0.50
0.52
0.54
0.56
Cro
ss-l
ink
den
sity
, Nc
CONCLUSION
This research study showed the effect of the high power ultrasound to initiate the polymerization of LDPE in the nano-size. The results predicted the effect of ultrasound on the structure of these polymer samples. Also, the results of XRD and ultrasonic wave velocities were found to be in good agreement with each other.
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