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TITLE
DEDICATION
CERTIFICATE 1
CERTIFICATE-2
DECLARATION
ACKNOWLEDGEMENT
CONTENTS
1. INTRODUCTION
1.1.Introduction
1.1.Latex
1.2. Primary processing
1.3. Properties
1.4. Product manufacture
1.5. Modified forms of NR
1.6. Physical modifications
1.6.1. Superior processing rubber
1.6.2. Viscosity stabilization
1.6.3. Oil extended NR (OENR)
1.6.4. Powdering / Granulation
1.6.5. Thermoplastic rubber
1.7. Chemical modifications
1.7.1. Grafting
1.7.2. Hydrogenation
1.7.3. Hydrohalogenation
1.7.4. Chlorination
1.7.5. Isomerization
1.7.6. Cyclization
1.7.7. ENPCAF modification
1.7.8. Maleic derivatives
1.7.9. Epoxidation
1.7.10. Depolymerization
1.8. Liquid rubbers
1.9. Economics of chemical modification
1.10. Degradation and stabilization of polymers
1.10.1. Thermal degradation
1.10.2. Oxidative degradation
1.10.3. Oxidized rubber
1.10.4. Termination
1.11. Depolymerized NR
1.12. Scope for present work
References
FIGURES
Fig.1.1 Modifications on NR
Fig.1.2. Natural rubber in India
2. EXPERIMENTAL TECHNIQUES
2.1. Experimental materials
2.1.1. Natural rubber
2.1.2. Peptizing agent
2.1.3. Nitrile rubber
2.1.4. Rubber chemicals
2.1.5. Other chemicals
2.2. Depolymerization
2.2.1. Thermal
2.2.2. Chemical
2.3. Compounding
2.4. Vulcanization
2.5. Viscosity measurements
2.5.1. Low viscosity
2.5.2. Medium viscosity
2.5.2.1. Brookfield viscometer
2.5.2.2. Rheomat 30
2.5.2.3. Haake rotoviscometer RV 1
2.5.3. High viscosity
2.5.3.1. Capillary rheometer
2.5.3.2. Test procedure
2.5.3.3. Extrudate swell
2.6. Thermal analysis
2.6.1. Differential scanning calorimeter
2.6.2. Thermogravimetry
2.7. Limiting oxygen index
2.8. Physical test methods
2.8.1. Modulus, tensile strength and elongation
2.8.2. Tear resistance
2.8.3. Hardness
References
FIGURES
Fig. 2.1. Drive unit of Haake viscometer
Fig. 2.1 Temperature vessel
Fig. 2.3. Range of viscosity masurements
Fig. 2.4. Capillary extrusion assembly
3. CHARACTERIZATION AND RHEOLOGICAL STUDIES ON LNR
3.1. Introduction
3.1.1. Viscosity
3.1.2. Coaxial cylinder viscometer
3.1.3. Wiesenberg effect
3.1.4. Temperature effect
3.1.5. Particle size effect
3.2. Experimental
3.2.1. Depolymerization
3.2.2. Rheomat 30
3.2.3. LNR
3.2.4. Temperature stabilization
3.3. Results and discussion
3.3.1. Properties
3.3.2. Viscosity studies
3.3.2.1. Shear rate-shear stress relationship
3.3.2.2. Effect of shear rate on viscosity
3.3.2.3. Effect of molecular weight on viscosity
3.3.2.4. Effect of temperature on viscosity
References
FIGURES
Fig. 3.1. Sketch of coaxial cylinder viscometer
Fig. 3.2.H NMR spectrum of LNRl
Fig. 3.3. IR spectrum of LNRI
Fig. 3.4. GPC of LNR samples
Fig. 3.5. Plots of shear rate vs shear stress
Fig. 3.6. Orientation of structure on shearing
Fig. 3.7. Temperature vs pseudoplasticity index
Fig. 3.8. Shear rate vs viscosity at 200C
Fig. 3.9. Normal stress effect
Fig. 3.10. Molecular weight vs viscosity
Fig. 3.1 1. Effect of temperature on viscosity
Fig. 3.12. 1/T vs viscosity
4. CHEMICAL MODIFICATION BY PHOSPHORUS ADDITION
4.1. Introduction
Epoxidation reaction
Side reactions
4.2. Preparation of LNR
4.3. Purification
4.4. Phosphorus modification
4.5. Results and discussion
References
FIGURES
Fig. 4.1.1H NMR spectrum of LNR
Fig, 4.2. I3C NMR spectrum of LNR
Fig. 4.3. IR spectrum of LNR
Fig. 4.4. 1H NMR spectrum of ELNR
Fig. 4.5.1H NMR spectrum of ELNR enlarged.
Fig. 4.6. 13C NMR spectrum of ELNR
Fig. 4.7. IR spectra of ELNR and separated fractions
Fig. 4.8. 1H NMR spectrum of ELNR.A
Fig. 4.9. 1H NMR spectrum nf Fl NR R
Fig. 4.10. 1H NMR spectrum of dichloromethane extract (1P1)
Fig. 4.11. 1H NMR spectrum of methanol solubles (2P1)
Fig. 4.12. 1H NMR spectrum of phosphorus modified polymer (2P2)
Fig. 4.13. 13C NMR spectrum of dichloromethane extract (IPI)
Fig. 4.14. 13C NMR spectrum of methanol solubles (2P1)
Fig. 4.15. 13C NMR spectrum of phosphorus modified polymer.
Fig. 4.16. 31P NMR spectrum of dibutylphosphate
Fig. 4.17. 31P NMR spectrum of dichloromethane extract (1P1)
Fig. 4.18. 31P NMR spectrum of methanol solubles
Fig. 4.19. 31P NMR spectrum of phosphorus modified polymer (2P2)
Fig. 4.20. DSC plots of modified polymer 1P2 and 2P2
Fig. 4.21. TGA curves of the modified polymers in nitrogen
Fig. 4.22. TGA curves of the modified polymers in air
Fig. 4.23. TGA curves of the modified polymers in oxygen
5. LIQUID NATURAL RUBBER AS A VISCOSITY MODIFIER IN NBR PROCESSING
5.1. Introduction
5.2. Experimental
5.2.1. Materials
5.2.2. Preparation of compounds
5.2.3. Testing
5.3. Results and discussion
5.3.1. Cure characteristics
5.3.2. Capillary rheometric studies
5.3.2.1. Shear stress vs. shear rate
5.3.2.2. Influence of shear rate on viscosity
5.3.2.3. Effect on flow index
5.3.2.4. Influence of temperature
5.3.2.5. Die swell
5.3.2.6. Effect of shear rate on melt elasticity
5.3.2.7. Vulcanizate properties
5.3.2.8. Evaluation of superposition shift factor
References
FIGURES
Fig. 5.1. Effect of plasticizers on cure.
Fig. 5.2. Shear stress vs shear rate at 90°C
Fig. 5.3. Viscosity vs shear rate at 900°C
Fig. 5.4. Influence of plasticizer on flow index
Fig. 5.5. Temperature vs viscosity and flow index
Fig. 5.6. Log viscosity vs 1/T
Fig. 5.7. Die swell (%) at 120°C
Fig. 5.8. Photograph of extrudates
Fig. 5.9. Melt elasticity at 333 s-1 and 120°C
Fig. 5.10. Physical properties of vulcanizates
Fig. 5.11. Dynamic properties of vulcanizates
Fig. 5.12. aT vs temperature
Fig. 5.13. Superposition master curve.
6. STRESS RELAXATION IN NITRILE RUBBER COMPOUNDS CONTAINING LNR
6.1. Introduction
6.2. Experimental
6.2.1. Materials
6.2.2. Compounding
6.2.3. Stress-strain measurements
6.3. Results and discussion
6.3.1. Cure
6.3.2. Modulus
6.3.3. Elongation at break
6.3.4. Stress relaxation
6.3.4.1. Relaxation at 200% strain
6.3.4.2. Relaxation at 50% strain
6.3.4.3. Prestretching
6.3.5. Effect of ageing
6.3.6. Permanent set
References
FIGURES
Fig.6.1. Effect of plasticizer on cure
Fig.6.2. Effect of plasticizer on modulus
Fig.6.3. Effect of plasticizer on elongation at break
Fig.6.4. Stress relaxation of DBP compounds a t 200% elongation
Fig.6.5. Stress relaxation of LNR compounds at 200% elongation
Fig.6.6. Effect of plasticiner on relaxation at 200% elongation
Fig.6.7. Stress relaxation of DBP compounds at 50% elongation.
Fig.6.8. Stress relaxation of LNR compounds at 50% elongation
Fig.6.9. Effect of plasticizer on relaxation at 50% elongation.
Fig.6.10. Relaxation after prestretching in DBP compounds at 50% elongation.
Fig.6.11. Relaxation after prestretching in LNR compounds at 50% elongation
Fig.6.12. Effect of plasticizer content after prestretching
Fig.6.13. Relaxation after ageing in DBP compounds
Fig.6.14. Relaxation after ageing in LNR compounds
Fig.G.15. Effect of plasticizer content after ageing.
7. PHYSICAL AND RHEOLOGICAL CHARACTERISTICS OF LIQUID NATURAL RUBBER MODIFIED BITUMEN
7.1. Introduction
7.2. Materials and methods
7.2.1. Bitumen
7.2.2. Liquid natural rubber
7.2.3. Preparation of samples
7.2.4. Viscosity measurements
7.2.5. Lap shear test
7.2.6. Softening point
7.2.7. Ductility
7.2.8. Penetration
7.3. Results and discussion
7.3.1. Liquid natural rubber
7.3.2. Softening point
7.3.3. Ductility
7.3.4. Penetration
7.3.5. Lap shear
7.3.6. Viscosity studies
7.3.6.1. Effect of shear rate
7.3.6.2. Effect of temperature
7.3.6.3. Effect of temperature on viscosity
7.3.6.4. Evaluation of superposition shift factor
7.3.7. Effect of LNR content
References
FIGURES
Fig. 7.1. Test samples for lap shear test
Fig. 7.2. GPC Chromatogram of LNR sample
Fig. 7.3. Influence of LNR on shear strength
Fig. 7.4. Shear stress vs shear rate at 100°C (B)
Fig 7.5. Shear stress vs shear rate at 100°C (BB)
Fig. 7.6. Shear stress vs temperature at 15 s-l (B)
Fig. 7.7. Shear stress vs temperature at 16.6 s-l (BB)
Fig. 7.8. Viscosity vs 1/T K (B)
Fig. 7.9. viscosity vs 1/T K (BB)
Fig. 7.10. Shift factor vs temperature
Fig. 7.11. Suerposition maser curve
Fig. 7.12. Effect of LNR on shear stress at 100°C (B)
Fig. 7.13. Effect of LNR on shear stress at 100°C (BB)
Fig. 7.14. Effect of LNR on Viscosity of soft bitumen (15 s-1)
Fig. 7.15. Effect of LNR on viscosity of blown bitumen (16.6 s-1)
8. FLAMMABILITY AND THERMAL PROPERTIES OF PHOSPHORUS MODIFED LIQUID NATURAL RUBBER
8.1.Introduction
8.1.1. Flammability
8.1.2. Ignition phenomena
8.1.3. Propagation
8.1.4. Extinction of polymer combustion
8.1.5. Phosphorus containing flame retardants
8.2. Experimental
8.3. Results and discussion
8.3.1. Properties of compounds
8.3.2. Vulcanizate properties
8.3.3. Thermogravimetric studies
8.3.4. Burning behaviour
References
FIGURES
Fig. 8.1. TGA Thermogram of compound A in air.
Fig. 8.2. TGA Thermogram of compound B in air
Fig. 8.3. TGA Thermogram of compound C in air
Fig. 8.4. TGA Thermogram of compound D in air
Fig. 8.5. TGA Thermogram of compound E in air.
Fig. 8.6. TGA Thermogram of compound F in air.
Fig. 8.7. TGA Thermogram of compound A in oxygen.
Fig. 8.8. TGA Thermogram of compound B in oxygen.
Fig. 8.9. TGA Thermograrn of compound C in oxygen
Fig. 8.10. TGA Thermogram of compound D in oxygen
Fig. 8.1 1. TGA Thermogram of compound E in oxygen
Fig. 8.12. TGA Thermogram of compound F in oxygen
Fig 8.13. Flame length for different concentrations of oxygen.
9. SUMMARY CONCLUSION AND SCOPE FOR FUTURE WORK
9.1. Summary
9.2. Conclusions
9.3. Scope for future work
CURRICULAM VlTE
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