vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
TITLE PAGE
i
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xiii
LIST OF FIGURES
xviii
LIST OF SYMBOLS
xxv
INTRODUCTION
1
1.1
Overview
1
1.2
Significance of Study
4
1.3
Objectives of Study
6
1.4
Outline of Thesis
7
LITERATURE REVIEW
9
2.1
Poly (vinyl chloride)
9
2.1.1
Definitions and General Feature Properties
9
2.1.2
PVC Polymerisation
11
2.1.3
Morphology of PVC
13
viii
2.1.4
PVC Fusion
16
2.1.4.1 Mechanisms of Fusion
17
2.1.4.2 Fusion Level Assessment:
Differential Scanning Calorimetry
19
2.1.4.3 Interrelation between Fusion and
Properties
2.2
2.3
2.4
21
PVC and Additives
24
2.2.1
Stabilizer
24
2.2.2
Lubricants
26
2.2.3
Processing Aid
32
2.2.4
Pigment
34
2.2.5
Impact Modifier
35
Impact Modification
38
2.3.1
Theory of Impact Modification
38
2.3.2
Impact Modified PVC
40
Filled PVC Composites
42
2.4.1
Composites: Definitions and Categories
42
2.4.2
Filler and Reinforcement
44
2.4.2.1 Mineral Fillers
46
2.4.2.2 Organic Fillers
47
Filler-Matrix Interface
50
2.4.3
2.4.3.1 Coupling Agent and Surface
Modification
2.5
Oil Palm Empty Fruit Bunch-Polymer Composites
2.5.1
56
Theory of Mechanical Properties of Filled
Composites
2.7
55
Utilization of EFB Fibre in Polymer
Composites
2.6
54
Oil Palm Empty Fruit Bunch and its
Chemical Composition
2.5.2
51
59
Recent Studies on Impact Modified PVC-U by
UTM researchers
63
ix
3
MECHANICAL PROPERTIES OF COMPRESSION
MOULDED PVC-U COMPOSITES
65
3.1
Introduction
65
3.2
Experimental
67
3.2.1
Materials
67
3.2.2
Filler Preparations
69
3.2.3
Coupling Agent Treatment of Filler
71
3.2.4
Blend Formulations
72
3.2.5
Dry Blending
82
3.2.6
Two Roll Milling
82
3.2.7
Compression Moulding
84
3.2.8
Density Determination
85
3.2.9
Impact Testing
87
3.3
3.2.10 Flexural Testing
87
3.2.11 Accelerated Weathering Testing
88
3.2.12 Water Absorption Testing
89
3.2.13 Scanning Electron Microscopy Study
89
3.2.14 Fourier Transform Infra-Red Analysis
90
Results and Discussion
90
3.3.1
3.3.2
Density of the Filler and EFB-filled PVC-U
Composites
90
Mechanical Properties
92
3.3.2.1 Notched Izod Impact Strength
92
3.3.2.2 Flexural Properties
108
3.3.2.3 EFB-Filled Acrylic-Impact Modified
PVC-U Composites Treated with
Coupling Agents
120
3.3.2.4 Effect of Accelerated Weathering on
the Impact and Flexural Properties
137
3.3.2.5 Effect of NPCC on the Impact and
Flexural Properties
153
3.3.2.6 Effect of Extracted Filler on the
Impact and Flexural Properties
159
x
3.3.2.7 Water Absorption
3.4
4
Conclusions
167
THERMAL PROPERTIES OF COMPRESSION
MOULDED PVC-U COMPOSITES
169
4.1
Introduction
169
4.2
Experimental
171
4.2.1
4.3
4.4
5
162
Materials, Filler Preparation and Blend
Formulations
172
4.2.2
Sample Preparation
172
4.2.3
Heat Deflection Temperature Testing
172
4.2.4
Differential Scanning Calorimetry Study
173
4.2.5
Thermogravimetric Analysis
173
Results and Discussion
174
4.3.1
Heat Deflection Temperature
174
4.3.2
Glass Transition Temperature
177
4.3.3
Thermal Degradation Temperature
178
Conclusions
190
PROCESSABILITY STUDIES OF PVC-U
COMPOUNDS
192
5.1
Introduction
192
5.2
Experimental
195
5.2.1
Materials and Blend Formulations
195
5.2.2
Filler Preparation
195
5.2.2.1 EFB Oil Extraction
195
5.2.3
Dry Blending
197
5.2.4
Processability Study
198
5.2.5
Fourier Transform Infra-Red Analysis
198
5.2.6
Scanning Electron Microscopy Study
199
5.3
Results and Discussion
199
5.3.1
Fusion Characteristics
199
5.3.1.1 Effect of EFB Filler
201
5.3.1.2 Effect of Acrylic Impact Modifier
203
xi
5.3.1.3 Effect of CPE Impact Modifier
207
5.3.1.4 Effect of Temperature
212
5.3.2
Postulated Lubrication Mechanisms
214
5.3.3
Effect of Extracted EFB Filler on the
Processability of PVC-U Compound
219
5.3.3.1 Extractives Removal
219
5.3.3.2 FTIR Spectra
219
5.3.3.3 Extracted Filler Surface
222
5.3.3.4 Fusion Characteristics of Extracted
EFB-Filled PVC-U Compound
5.4
6
Conclusions
223
225
EXTRUSION PROCESS AND MECHANICAL
PROPERTIES OF EXTRUDATES
227
6.1
Introduction
227
6.2
Experimental
229
6.2.1
Materials
229
6.2.2
Dry Blending
230
6.2.3
Extrusion Process
230
6.2.4
Izod Impact and Flexural Testing
231
6.2.5
Tensile Testing
232
6.2.6
Differential Scanning Calorimetry Study
232
6.3
Results and Discussion
232
6.3.1
Extrudates Characteristics
233
6.3.2
Differential Scanning Calorimetry
238
6.3.3
Impact Strength
240
6.3.3.1 Effect of Processing Temperature
240
6.3.3.2 Effect of Screw Speed
244
Flexural Properties
246
6.3.4.1 Effect of Processing Temperature
246
6.3.4.2 Effect of Screw Speed
248
6.3.5
Tensile Properties
249
6.3.6
Yield Stress Analysis
255
6.3.7
General Discussion
258
6.3.4
xii
6.4
7
Conclusions
260
CONCLUSIONS AND SUGGESTIONS
FOR FUTURE WORK
262
7.1
Conclusions
262
7.2
Suggestions for Future Work
264
REFERENCES
266-282
xiii
LIST OF TABLES
TABLE NO.
2.1
TITLE
PAGE
Some physical properties of moulding PVC products
and compounds
11
2.2
PVC nomenclatures
15
2.3
Chemical analysis of EFB
55
3.1
Specifications of PVC suspension resin MH-66
68
3.2
Types of additives
68
3.3
Blend formulations
73
3.4
Effect of impact modifiers content on the impact strength
of PVC-U compounds
3.5
94
Percentage of impact strength reduction of EFB-filled
impact modified composites as filler content increased
from 10 to 40 phr
3.6
101
Percentage of impact strength increment for EFB-filled
impact modified composites as the impact modifier
content increased from 0 to 12 phr
3.7
107
Percentage of flexural modulus increment for EFB-filled impact
modified composites as the filler content increased
from 0 to 40 phr
3.8
114
Percentage of flexural strength reduction for EFB-filled
impact modified composites as the filler content increased
from 0 to 40 phr
3.9
Percentage of flexural modulus reduction for EFB-filled
impact modified composites as the impact modifier
114
xiv
increased from 0 to 12 phr
3.10
118
Percentage of flexural strength reduction for EFB-filled
impact modified composites as the impact modifier
increased from 0 to 12 phr
3.11
Impact strength of EFB–filled acrylic-impact modified
composites treated with Prosil 9234 and NZ 44
3.12
130
Comparison between the predicted and the experimental
of relative modulus of composites
3.15
130
Flexural strength of EFB–filled acrylic-impact modified
composites treated with Prosil 9234 and NZ 44
3.14
126
Flexural modulus of EFB–filled acrylic-impact modified
composites treated with Prosil 9234 and NZ 44
3.13
118
131
Comparison between the predicted and the experimental
of relative modulus of filled acrylic-impact modified composites
at 3 phr of acrylic
3.16
132
Comparison between the predicted and the experimental
of relative modulus of filled acrylic-impact modified
composites at 6 phr of acrylic
3.17
132
Comparison between the predicted and the experimental
of relative modulus of filled acrylic-impact modified composites
at 9 phr of acrylic
3.18
132
Comparison between the predicted and the experimental relative
flexural modulus of filled acrylic-impact modified composites at
12 phr of acrylic
3.19
Impact strength reduction for impact-modified compounds after
accelerated weathering for 504 hours
3.20
139
Percentage of impact strength reduction for filled impact modified
composites after weathered for 504 hours
3.21
133
142
Percentage of flexural modulus reduction and percentage of
flexural strength increment of the impact-modified compounds
after 504 hours exposure to accelerated weathering
3.22
Percentage of flexural modulus reduction and percentage
of flexural strength increment of the filled composites and filled
impact-modified composites after 504 hours exposure
146
xv
to accelerated weathering
3.23
Percentage of water absorption of impact modified
compounds and EFB-filled composites
3.24
163
Percentage of water absorption of impact modified
compounds and impact modified treated composites
4.1
146
166
HDT of acrylic-impact modified and CPE-impact
modified PVC-U compounds
175
4.2
HDT of EFB-filled PVC-U composites
176
4.3
HDT of EFB-filled acrylic-impact modified and
EFB-filled CPE-impact modified PVC-U composites
176
4.4
Tg of EFB-filled PVC-U composites
177
4.5
Tg of EFB-filled acrylic-impact modified and EFB-filled
CPE-impact modified PVC-U composites
4.6
Degradation temperature of neat components obtained
from TG and DTG curves
4.7
185
Degradation temperature of EFB-filled CPE-impact
modified PVC-U composites
4.9
180
Degradation temperature of EFB-filled PVC-U
composites obtained from TG and DTG curves
4.8
178
187
Degradation temperature of EFB-filled acrylic-impact
modified PVC-U composites obtained from TG and DTG
curves
5.1
Fusion characteristics of EFB-filled compounds at
50 rpm and 80 oC
5.2
202
Fusion characteristics of acrylic-impact modified
compounds at 50 rpm and 180 oC
5.3
189
204
Fusion characteristics of EFB-filled acrylic-impact
modified compounds added with 9 phr of acrylic at
50 rpm and 180 oC
5.4
205
Fusion characteristics of EFB-filled acrylic-impact
modified compounds filled with 20 phr of filler at
50 rpm and 180 oC
5.5
206
Fusion characteristics of CPE-impact modified
compounds at 50 rpm and 180 oC
208
xvi
5.6
Fusion characteristics of EFB-filled CPE-impact modified
compounds added with 9 phr CPE at 50 rpm and 180 oC
5.7
Fusion characteristics of EFB-filled CPE-impact modified
compounds filled with 20 phr of EFB at 50 rpm and 180 oC
5.8
211
Fusion time of PVC-U compounds at different processing
temperatures and constant rotor speed of 50 rpm
5.9
210
212
End torque of PVC–U compounds and composites at
different processing temperatures and constant rotor speed
of 50 rpm
5.10
214
Fusion characteristics of extracted EFB-filled PVC-U
compounds at 50 rpm and 180 oC.
224
6.1
The conditions of extrusion processing
231
6.2
Residence time of extrudates at constant die temperature
237
6.3
Residence time of extrudates at constant screw speed of 60 rpm
238
6.4
Heat of fusion of extrudates at screw speed of 60 rpm
240
6.5
Effect of processing temperatures on the fracture properties
of unfilled and filled extrudates
6.6
Effect of processing temperatures on the heat of fusion and
impact strength of unfilled extrudates
6.7
247
Effect of screw speeds on the flexural modulus of unfilled
and filled extrudates
6.14
247
Effect of processing temperatures on the flexural strength of
unfilled and filled extrudates
6.13
246
Effect of processing temperatures on the flexural modulus of
filled extrudates
6.12
244
Effect of processing temperatures on the flexural modulus
of unfilled extrudates
6.11
244
Effect of screw speeds on the impact strength of unfilled
and filled extrudates
6.10
243
Effect of screw speeds on the fracture properties of unfilled
and filled extrudates
6.9
241
Effect of processing temperatures on the heat of fusion and
impact strength of filled extrudates
6.8
241
Effect of screw speeds on the flexural strength of unfilled
249
xvii
and filled extrudates
6.15
Effect of processing temperatures on the yield stress of
unfilled extrudates at screw speed of 60 rpm
6.16
258
Predicted yield stress of extrudates at 3 m/s, die temperature
of 190 oC and screw speed of 60 rpm
6.24
255
Predicted yield stress of extrudates at 3 m/s, die temperature
of 180 oC and screw speed of 60 rpm
6.23
255
Effect of strain rate on the yield stress of unfilled and filled
extrudates
6.22
254
Effect of screw speed on the percentage strain at break at die
temperature of 180 oC
6.21
254
Effect of processing temperature on the percentage strain
at break of filled extrudates at screw speed of 60 rpm
6.20
251
Effect of processing temperature on the percentage strain
at break of unfilled extrudates at screw speed of 60 rpm
6.19
251
Effect of screw speeds on the yield stress of extrudates
at die temperature of 180 oC
6.18
250
Effect of processing temperature on the yield stress of
filled extrudates at screw speed of 60 rpm
6.17
249
258
Impact strength, yield stress and strain at break at die
temperature 180 oC and 190 oC
259
xviii
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
2.1
The chemistry of vinyl chloride monomer production
12
2.2
PVC particle morphology
15
2.3
Mechanism of fusion during processing extruder
18
2.4
Schematic presentation of fusion process for
19
2.5
DuPont thermal analysis of PVC-U compound
compression moulded at different temperatures
2.6
20
Zip-elimination of HCl from PVC and simultaneous
formation of sequences containing conjugated
double bonds (polyenes) in the chain during degradation
2.7
25
A model of PVC lubrication (not to scale) showing metal
lubrication and lubrication between PVC primary particle
flow units for (a) no lubricant; (b) calcium stearate ;
(c) for paraffin ; and (d) calcium stearate and paraffin
2.8
29
Lubrication mechanism, showing metal lubrication
and lubrication between PVC micro particles flow units
of PVC/CPE, PVC/OPE and PVC/CPE/OPE compounds
2.9
31
Stress distribution in polymer matrix surrounding
a rubbery impact modifier particle
37
2.10
Aspect ratio calculation
46
2.11
Cellulose molecular structure
48
2.12
Bonding mechanism of silane coupling agent to filler’s surface
52
3.1
Chemical structure of (a) Prosil 9234 (b) NZ 44
69
3.2
EFB fillers distribution
70
xix
3.3
Morphology of EFB fillers (Magnification of 600x)
70
3.4
Two roll milling of PVC-U dry blend at 165 oC
83
3.5
Two-roll milled composite sheet
83
3.6
A mould with five cavities placed in between the hot platens
before compression
3.7
The theoretical and experimental densities of EFB-filled
composites (S9 - S12) with respect to EFB filler contents
3.8
84
91
SEM micrograph of impact-fractured surface of S11
(Magnification 2000x)
92
3.9
Hinge breaks of impact-modified PVC-U samples (S3)
95
3.10
SEM micrograph of impact-fractured surface of S0
(Magnification 200x)
3.11
SEM micrograph of impact-fractured surface of S3
(Magnification 200x)
3.12
96
SEM micrograph of impact-fractured surface of S7
(Magnification 200x)
3.13
96
97
Effect of filler content on the impact strength of EFB-filled
composites (S9-S12) and EFB-filled acrylic-impact modified
composites (S13-S28)
3.14
98
Effect of filler content on the impact strength of EFB-filled
composites (S9-S12) and EFB-filled CPE-impact modified
composite (S29- S44)
3.15
SEM micrograph of the impact-fracture surface of composite
incorporated with 10 phr filler (Magnification 500x)
3.16
100
Polar-polar interaction between PVC molecule and
cellulose molecule.
3.20
100
SEM micrograph of the impact-fractured surface of composite
incorporated with 40 phr filler (Magnification 500x)
3.19
99
SEM micrograph of the impact-fractured surface of composite
incorporated with 30 phr filler (Magnification 500x)
3.18
99
SEM micrograph of the impact-fracture surface of composite
incorporated with 20 phr filler(Magnification 500x)
3.17
98
SEM micrograph of filler debonding on the impact-fractured
102
xx
surface of composite incorporated with 30 phr filler
(Magnification 900x)
3.21
103
SEM micrograph of filler bundles pulled-out area on the impactfractured surface composite incorporated with 30 phr filler of S11
(Magnification 1000x)
3.22
Effect of acrylic content on the impact strength of EFB-filled
acrylic-impact modified composites (S0-S4 and S9-S28).
3.23
104
105
Effect of CPE impact modifier content on the impact
strength of EFB-filled CPE-impact modified composites
(S5 -S8 and S29-S44)
3.24
Effect of acrylic and CPE impact modifier on the impact
strength of EFB-filled impact-modified composites
3.25
116
Effect of filler and CPE content on the flexural strength of
EFB-filled CPE-impact modified composites (S29 - S44)
3.35
116
Effect of filler and CPE content on the flexural modulus of
EFB-filled CPE-impact modified composites (S29 -S44)
3.34
115
Effect of filler and acrylic content on the flexural strength of
EFB-filled acrylic-impact modified composites (S13-S28)
3.33
113
Effect of filler and acrylic content on the flexural modulus of
EFB-filled acrylic-impact modified composites (S13-S28)
3.32
112
Effect of filler and CPE content on the flexural strength of
EFB-filled CPE-impact modified composites (S29-S44)
3.31
112
Effect of filler and CPE content on the flexural modulus of
EFB-filled CPE-impact modified composites (S29-S44)
3.30
111
Effect of filler and acrylic content on the flexural strength of
EFB-filled acrylic-impact modified composites (S9-S28)
3.29
109
Effect of filler and acrylic content on the flexural modulus
of EFB-filled acrylic-impact modified composites (S9-S28)
3.28
109
Effect of impact modifiers content on the flexural strength
of impact modified compounds (S0-S8).
3.27
107
Effect of impact modifiers content on the flexural modulus
of impact modified compounds (S0-S8)
3.26
105
Effect of acrylic and CPE impact modifier on the flexural
117
xxi
modulus of EFB-filled impact modified composites
3.36
Effect of acrylic and CPE impact modifier on the flexural
strength of EFB-filled impact modified composites
3.37
119
119
Effect of EFB filler and acrylic content on the impact strength
of EFB-filled acrylic-impact modified composites treated
with Prosil 9234 (S49-S68)
3.38
121
Effect of EFB filler and acrylic content on the impact strength
of EFB-filled acrylic-impact modified composites treated
with NZ 44 (S69-S88)
3.39
Bonding mechanism of NZ 44 coupling agent to
the filler’s surface
3.40
121
122
SEM micrographs of the impact fractured-surface of composites
(a) Prosil 9234 treatment (S51) (Magnification 100x) (b) S51
(Magnification 2000x) (c) NZ 44 treatment (S71)
(Magnification 500x) and (d) S71 (Magnification 2000x)
3.41
125
Effect of EFB filler and acrylic contents on the flexural modulus
of EFB-filled acrylic-impact modified composites treated with
Prosil 9234 (S9-S28 and S49-S68)
3. 42
127
Effect of EFB filler and acrylic contents on the flexural strength
of EFB-filled acrylic-impact modified composites treated with
Prosil 9234 (S9-S28 and S49-S68)
3.43
128
Effect of EFB filler and acrylic contents on the flexural modulus
of EFB-filled acrylic-impact modified composites treated with
NZ 44 (S9-S28 and S69-S88)
3.44
128
Effect of EFB filler and acrylic content on the flexural strength
of EFB-filled acrylic-impact modified composites treated with
NZ 44 (S9-S28 and S69-S88)
129
3.45
FTIR spectra of (a) PVC-U compound (S0) (b) composite (S11)
135
3.46
FTIR spectra of (a) filled composite (S11) (b) Prosil 9234-treated
filled composite (S51) (c) NZ 44-treated filled PVC-U
composite (S71).
3.47
Impact strength of unweathered and weathered impact modified
compounds
3.48
137
Impact strength of unweathered and weathered EFB filled
138
xxii
composites
3.49
Suggested reaction scheme for the accelerated photo-oxidation
degradation
3.50
155
Effects of EFB (S9-S12) and NPCC (S89-S91) on the flexural
modulus of composites
3.65
154
Effects of 10 phr NPCC, 20 phr NPCC, 3 phr acrylic and
3 phr CPE on the impact strength of EFB-filled composites
3.64
153
Effects of EFB filler and NPCC on the impact strength of
composites
3.63
152
FTIR spectra of unweathered and weathered-acrylic-impact
modified composites
3.62
152
FTIR spectra of (a) unweathered and (b) weathered-acrylic
impact modified composites
3.61
151
FTIR spectra of (a) unweathered and (b) weathered-EFB-filled
composites
3.60
149
FTIR spectra of (a) unweathered and (b) weathered PVC-U
compounds
3.59
148
Appearance of some samples surface before and after exposed
to UV irradiation for 504 hours
3.58
148
Flexural strength of unweathered and weathered EFB-filled
impact modified composites
3.57
147
Flexural modulus of unweathered and weathered EFB-filled
impact modified composites
3.56
147
Flexural strength of unweathered and weathered EFB-filled
composites
3.55
145
Flexural modulus of unweathered and weathered EFB-filled
PVC-U composites
3.54
145
Flexural strength of unweathered and weathered impact
modified compounds
3.53
143
Flexural modulus of unweathered and weathered impact
compounds
3.52
141
Impact strength of unweathered and weathered EFB-filled
impact modified PVC-U composites
3.51
140
Effects of EFB (S9-S12) and NPCC (S89-S91) on the flexural
156
xxiii
modulus of composites
3.66
Effects of 10 phr NPCC, 20 phr NPCC, 3 phr acrylic and
3 phr CPE on the flexural modulus of the EFB-filled composites
3.67
161
Effect of unextracted and extracted EFB filler on the flexural
strength of composites at filler content of 30 phr
3.71
160
Effect of unextracted and extracted EFB filler on the flexural
modulus of composites at filler content of 30 phr
3.70
159
Effect of unextracted and extracted EFB filler on the impact
strength of composites at filler content of 30 phr
3.69
158
Effects of 10 phr NPCC, 20 phr NPCC, 3 phr acrylic and
3 phr CPE on the flexural strength of the EFB-filled composites
3.68
157
162
Effects of impact modifier content on water absorption of
acrylic-impact modified (S1-S4) and CPE-impact modified
compounds (S5-S8)
3.72
Effect of EFB filler content on the water absorption of
unmodified and modified composites
3.73
164
Effect of coupling agents on the water absorption of treated
unmodified composites
3.74
163
165
Effect of coupling agents on the water absorption of treated
acrylic-impact modified composites
166
4.1
(a) TG and (b) DTG curves for neat components
179
4.2
DSC trace of EFB filler
181
4.3
(a) TG and (b) DTG curves of unmodified filled PVC-U
composites
184
4.4
Polar-polar interaction between H20 and PVC molecules
185
4.5
(a) TG and (b) DTG curves for EFB-filled CPE-impact
modified PVC-U composites
187
4.6
(a) TG and (b) DTG curves for EFB filled acrylic-impact PVC-U 188
4.7
Polar interaction between MMA and HCl
189
5.1
Rigid PVC fusion mechanism in the Torque Rheometer
193
5.2
Soxhlet extraction apparatus
197
5.3
A typical temperature and torque curves of PVC-U
compound (S0) blended in the Brabender Torque Rheometer
200
xxiv
5.4
A typical temperature and torque curves of EFB-filled PVC-U
composite (S0) blended in the Brabender Torque Rheometer
5.5
201
Postulated lubrication mechanism of among PVC micro-particles
flow units, EFB fillers and acrylic impact modifiers
5.6
217
Postulated lubrication mechanism of among PVC micro-particles
flow units, EFB fillers and CPE impact modifiers
218
5.6
FTIR spectra: a) EFB filler b) extracted EFB filler
220
5.7
FTIR spectra (a) solvents mixture condensate
(b) concentrated extract
221
5.8
Palm oil molecular structure
222
5.9
SEM Micrograph for EFB Filler (Magnification 3000x)
223
5.10
SEM micrograph for extracted EFB filler (Magnification 1000x)
6.1
223
o
Extrudates of S0, S3, S7, S9 and S21 at die temperature of 185 C,
and extrudate of S37 at die temperature of 190 oC
233
6.2
Shape difference between the die and extrudate
234
6.3
Filled extrudates of S37 at die temperature of 180 oC and 185 oC
and at constant screw speed of 60 rpm
6.4
235
Filled extrudate of S9 with air bubbles on surface
236
o
6.5
Filled extrudates of S10, S22 and S38 at die temperature of 195 C
6.6
A typical DSC thermogram of S0 at different processing
temperatures
6.7
6.8
237
239
A typical stress-strain graph of tensile for extrudates at 60 rpm
and 180 oC
253
Predicted yield stress values at 3 m/s for S0
257
xxv
LIST OF SYMBOLS
b
-
width
d
-
thickness
CPE
-
chlorinated polyethylene
EFB
-
oil palm empty fruit bunch
Ec
-
flexural modulus of composite
Ep
-
flexural modulus of polymer
Gf
-
shear modulus of filler
Gp
-
shear modulus of polymer
HDT
-
heat deflection temperature
k
-
Boltzmann’s constant
L
-
span
Mt
-
water absorption at time t
NPCC
-
nano-precipitated calcium carbonate
NZ 44
-
zirconate based coupling agent
Prosil 9234
-
silane based coupling agent
PVC-U
-
unplasticised poly (vinyl chloride)
S
-
sample
Tg
-
glass transition temperature
TG
-
thermogravimetric curve
DTG
-
differential thermogravimetric curve
v
-
velocity
Vf
-
volume of filler
Vp
-
volume pyknometer
Vw
-
volume of water
W
-
failure load
xxvi
Wadditives
-
weight fraction of additives
Wd
-
dry weight
Wf
-
weight fraction of filler
Wpvc
-
weight fraction of poly (vinyl chloride)
Ww
-
weight after immersed into water
∆H
-
activation energy
∆S
-
deflection increment
∆W
-
load increment
ε
-
strain rate
εc
-
elongation at break of composite
εp
-
elongation at break of polymer
φf
-
volume fraction of filler
φm
-
maximum packing fraction
γ
-
stress concentration factor
ν
-
activation volume
νp
-
Poisson’s ratio of polymer
ρadditives
-
density of additives
ρc
-
density of composite
ρf
-
density of filler
ρw
-
density of water
σc
-
strength of composite
σp
-
strength of polymer
σy
-
yield stress
ψ
-
reduced concentration term