Online Thesis Search Results

TITLE
DEDICATION
CERTIFICATE
DECLARATION
ACKNOWLEDGEMENT
GLOSSARY OF TERMS
CONTENTS
PREFACE
1. Introduction
1.1 Physical blends
1.1. 1 Miscible blends
1.1.2 Compatible blends
1.1.3 Incompatible blends
1.1.4 Polymer alloys
1.2 Interpenetrating network polymers
1.3 Copolymers
1.3.1 Alternating copolymers
1.3.2 Random copolymers
1.3.3 Graft copolymers
1.3.4 Block copolymers
1.4 A review on block copolymers
1.4.1 Architectural variation
Fig.1.1 Representation of various block copolymer architectures.
Fig.1.2 Radial block copolymer architecture.
1. 4.2 Synthetic methods
1.4.2.1 Living polymerisation (sequential addition process)
1.4.2.2 Step-growth polymerisation (Interactions of functionally terminated oligomers)
1.4.2.3 Polymer growth from oligomer end groups
1.4.3 Morphology of block copolymers
1.4.4 Commercial importance of block copolymers
1.5 Thermoplastic elastomers
1.5.1 Commercial grade thermoplastic elastomers
1.5.1.1 Styrene-based block copolymers
1.5.1.2 Polyether-ester
1.5.1.3 Polyurethane block copolymers
(i) Cast elastomers
(ii) Millable elastomers
(iii) Polyurethane thermoplastic elastomers
a. Synthesis of polyurethane elastomers
b. Properties
c. Morphological features of block copolyurethanes
Fig.1.4 Shematic rnorrphology of polyurethane thermoplastic elastomer.
d. Effect of hard segment on the properties of polyurethane elastomers
e. Effect of chain extenderr
f. Effect of diisocyanate.
g. Effect of hydrogen bonding
h. Effect of soft segment on the properties of the polyurethane elastomers
1.6 Scope of the present work
1.6.1 Objectives of the work
1.7 References
2. Experimental
2.1 Materials
2.2 Experimental
2.2.1 Preparation of hydroxyl terminated liquid natural rubber
2.2.2 Block copolymer synthesis
2.2.2.1 One-shot process
2.2.2.2 Two-shot process
Table 2.1 Overall compositions of the block copolymers of NR/EG (one-shot and two-shot)
Table 2.2 Overall compositions of the block copolymers of NR/PG (one-shot and two-shot)
2.2.3 Polymer designation
Table 2.3 Overall compositions of the block copolymers of NR/1, 3-BDO NR/1, 4-BDO (one-shot and two-shot)
Table 2.4 Overall compositions of the block copolymers of NR/BPA (one- shot and two-shot)
Table 2.5 Optimum amount of catalyst in synthesis with various chain extenders (One-shot and Two-shot)
2.2.4 Chemical methods of analysis
2.2.4.1 Estimation of hydroxyl groups
2.2.4.2 Determination of epoxy value
2.2.4.3 Determination of iodine value
(i) Wijs method for the determination of iodine value
2.2.4.4 Determination of carbonyl value
2.2.5 Instrumental methods of analysis
2.2.5.1 Determination of molecular weight
2.2.5.2 Infrared spectral analysis
2.2.5.3 Differential scanning calorimetric analysis
2.2.5.4 Thermogravimetric analysis
2.2.5.5 Scanning electron microscopy analysis
2.2.5.6 Stress-strain behaviour
2.2.5.7 Tear strength
2.2.5.8 Hardness
2.3 References
3. Results and Discussion
3.1 Preliminary studies
3.1.1 Hydroxyl terminated liquid natural rubber
Fig.3.1 IR spectrum of liquid NR
Table 3.1 IR peak assignment of the liquid NR
Table 3.2 Data obtained from the chemical analysis of the liquid NR.
3.1.2 Standardisation of the method of block copolymer synthesis
3.2 IR studies
3.2.1 Course of reaction
3.3 Thermogravimetric analysis
Table 3.8 Data from TGA of NR/EG block copolymers (one-shot and two-shot)
Table 3.9 Data from TGA of NR/PG block copolymers (one-shot and two-shot)
Table 3.10 Data from TGA of NR/1, 3-BDO block copolymers (one-shot and two-shot)
Table 3.11 Data from TGA of NR/1, 4-BDO block copolymers (one-shot and two-shot)
Table 3.12 Data from TGA of NR/BPA block copolymers (one-shot and two-shot)
Fig.3.13 Onset of mass loss (first stage) versus hard segment content of thetwo- shot block of polymers.
Fig.3.14 Plot of first stage peak temperature versus hard segment content of thetwo-shot block col) olymers.
Fig.3.15 Plot of second stage onset temperature versus soft segment content of thetwo-shot block copolymers.
Fig.3.16 Plots of second stage peak temperature versus soft segment content of the two-shot block copolymers.
3.4 Differential scanning calorimetric analysis
3.4.1 DSC analysis of NR/EG block copolymer
3.4.1.1 Two-shot products
Table 3.13 DSC results of NR/EG block copolymers (two-shot and one shot)
Fig.3.18 Plot of Tg values versus hard segment content of the two-shot block copolymers.
3.4.1.2 One-shot products
3.4.2 DSC analysis of NR / PG block copolymers
3.4.2.1 Two-shot products
Table 3.14 DSC results of NRIPG block copolymers (two-shot and one-shot)
3.4.2.2 One-shot products
3.4.3 DSC analysis of the NR / 1, 3-BDO block copolymers
3.4.3.1 Two-shot products
Table 3.15 DSC results of NR/1, 3-BDO block copolymers (two-shot and one-shotproducts)
3.4.3.2 One-shot product
3.4.4 DSC analysis of the NR 1, 4-BDO block copolymers
3.4.4.1 Two-shot products
Table 3.16 DSC results of NR/1, 4 BDO block copolymers (two-shot and one-shotproducts)
3.4.4.2 One-shot product
3 4.5 DSC analysis of the NR / BPA block copolymers
3.4.5.1 Two-shot products
Table 3.17 DSC results of NR/BPA block copolymers (two-shot and one-shot)
3.4.5.2 One-shot product
3.4.6 A comparative account of the DSC analysis
3.5 Implication of DSC and TGA results
Table 3.18 Comparison of peak temperature (OC) of the final endotherm in DSC thermogram (I) with the peak temperature of the hard segment degradation in TGA thermogram (II) (two-shot products)
3.6 Stress-strain behaviour
3.6.1 Tensile measurements of NR / EG block copolymers
3.6.1.1 Two-shot products
Fig.3.23 Stress-strnin curves of two-shot products of NR/EG
Table 3.19 Tensile properties of the NR/EG block copolymers (two-shot)
3.6.1.2 One-shot products
Fig. 3.24 Stress-strain curves of one-shot products of NR/EG.
Table 3.20 Tensile properties of the NR/EG block copolymers (one- shot)
3.6.2 Tensile measurements of NR / PG block copolymers
3.6.2.1 Two-shot products
Fig. 3.25 Stress-strain curves of two-shot products of NR/PG.
Table 3.21 Tensile properties of the NR/PG block copolymers (two-shot)
3.6.2.2 One-shot product
Fig.3.26 stress-strain curves of one-shot products of NR/PG.
Table 3.22 Tensile properties of the NR/PG block copolymers (one-shot)
3.6.3 Tensile measurements of NR / 1, 3-BDO block copolymers
3.6.3.1 Two-shot products
Fig.3.27 Stress-strain curves of two-shot products of NR/1, 3-BDO.
Table 3.23 Tensile properties of NR/1, 3-BDO block copolymers (two-shot)
3.6.3.2 One-shot products
Fig.3.28 Stress-strain curves of one-shot products of NR/1, 3-BDO.
Table 3.24 Tensile propertic! of 1, 3-BDO block copolymers (one-shot)
3.6.4 Tensile measurements of NR / 1, 4-BDO block copolymers
3.6.4.1 Two-shot products
Fig.3.29 Stress-strain curves of two-shot products of NR/1, 4-BDO.
Table 3.25 Tensile properties of NR/1, 4-BDO block copolymers (two-shot)
3.6.4.2 One-shot products
Fig.3.30 Stress-strain curves of one-shot products of NR/l, 4-BDO.
Table 3.26 Tensile properties of NR/l, 4-BDO block copolymers (one-shot)
3.6.5 Tensile measurements of NR / BPA block copolymers
3.6.5.1 Two-shot products
Fig.3.31 Stress-strain curves of one-shot products of NR/BPA block of polymers.
Table 3.27 Tensile properties of NR/BPA block copolymers (two-shot)
3.6.5.2 One-shot products
Fig.3.32 Stress-strain curves of one-shot products of NR/BPA.
Table 3.28 Tensile properties of NIR/BPA block copolymers (one-shot)
3.6.6 A comparative-account of the tensile properties
Fig.3.34 Hard segment content versus tensile strength (two-shot)
Fig.3.35 Hard segment content versus modulus of elasticity
Fig.3.36 Hard segment content versus elongation at break.
Fig.3.37 soft segment content versus elongation at break.
3.6.7 Comparison of the tensile properties of one-shot and two-shot products
Table 3.29 Comparison of tensile strength of the one-shot and two-shot block copolymers of all series.
Table 3.30 Comparison of modulus of elasticity of the one-shot and two-shot block copolymers of all series.
Table 3.31 Comparison of elongation at break of the one-shot and two-shot block copolymers of all series.
3.7 Fractographic studies using SEM
3.7.1 Fractography of NR / EG block copolymers
3.7.1.1 Two-shot products
Fig. 3.38 Tensile fractograph of NR/EG (70/30) -2
Fig.3.39 Tensile fractograph of NR/EG (50/50) -2
Fig.3.40 Tensile fractograph of NR/EG (30/70) -2
Fig.3.60 Tensile fractograph of NR/EG (30/70) -2
Fig.3.41 Tensile fractograph of NR/PG (70/30) -2
Fig.3.42 Tensile fractograph of NR/PG (60/40) -2
Fig.3.44 Tensile fractograph of NR/PG (40/60) -2
Fig.3.45 Tensile fractograph of NR/PG (30/70) -2
Fig.3.46 Tensile fractograph of NR/1, 3-BDO (70/30) -2
Fig.3.47 Tensile fractograph of NR/1, 3-BDO (60/40) -2
Fig.3.48 Tensile fractograph of NR/1, 3-BDO (50/50) -2
Fig.3.50 Tensile fractograph of NR/1, 3-BDO (30/70) -2
Fig.3.51 Tensile fractograph of NR/1, 4-BDO (70/30) -2
Fig.3.52 Tensile fractograph of NR/1, 4 -BDO (50/50) -2
Fig. 3.53 Tensile fractograph of NR/l, 4-BDO) (30/70) -2
Fig.3.54 Tensile fractograph of NR/l, 4-BDO (70/30) -1
Fig.3.55 Tensile fractograph of SR/BPA (70/30) -2
Fig.3.56 Tensile fractograph of NR/BPA (60/40) -2
Fig.3.57 Tensile fractograph of NR/BPA (50/50) -2
Fig.3.58 Tensile fractograph of INR/BPA (40/60) -2
Fig. 3.59 Tensile fractograph of NR/BPA (50/50) -1
Fig.3.61Tensile fractograph of NR/BPA (50/50) -2
3.7.2 Fractography of NR / PG block copolymers
3.7.2.1 Two-shot products
3.7.3 Fractography of NR/1, 3-BDO block copolymers
3.7.3.1 Two-shot products
3.7.4 Fractography of NR / 1, 4-BDO block copolymers
3.7.4.1 Two-shot products
3.7.4.2 One-shot products
3.7.5 Fractography of NR / BPA block copolymers
3.7.5.1 Two-shot products
3.7.5.2 One- shot products
3.8 Morphology of the block copolymers
3.8.1 NR / EG block copolymers
3.8.1.1 Two-shot products
3.8.2 NR / PG block copolymers
3.8.2.1 Two-shot products
3.8.3 NR / 1, 3-BDO block copolymers
3.8.3.1 Two-shot products
3.8.4 NR / 1, 4-BDO block copolymers
3.8.4.1 Two-shot products
3.8.4.2 One-shot products
3.8.5 NR / BPA block copolymers
3.8.5.1 Two-shot products
3.8.5.2 One-shot products
3.8.6 General observations regarding morphology
3.9 Tear strength
3.9.1 Two-shot products
Fig.3.62 Hard segment content versus tear strength (two-shot)
Table 3.32 Tear strength of various block copolymers by two-shot process.
Fig.3.63 Tear fractograph of NR/BPA (70/30) -2
FIg.3.64 Tear fractograph of NR/EG (70/30) -2
Fig.3.65 Tear fractograph of NR/PG (70/30) -2
Fig.3.66 Tear fractograph of NR/1, 4-BDO (70/30) -2
Fig.3.67 Tear fractograph of NR/BPA (50/50) -2.
Fig.3.68 Tear fractograp of NR/1, 3-BD0 (50/50) -2.
3.9.2 One-shot products
Fig.3.69 Hard segment content versus tear strength (one-shot)
Table 3.33 Tear strength of variou block copolymers by one-shot process.
3.10 Hardness
3.10.1 Two-shot products
Fig.3.70 Hardness versus hard segment content of the block copolymers (two-shot)
Table 3.34 Shore A hardness of various block copolymers prepared by two-shotprocess.
3.10.2 One-shot products
Fig.3.71 Hardness versus hard segment content of the block copolymers (one-shot)
Table 3.35 Shore A hardness of various block copolymers prepared by one-shot process.
3.11 Effect of diisocyanate structure on the block copolymer properties
3.12 References
4. Summary and Conclusion
Scope for further studies
APPENDIX
List of Publications