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  • TITLE
  • DEDICATION
  • CERTIFICATE
  • DECLARATION
  • ACKNOWLEDGEMENT
  • GLOSSARY OF TERMS
  • CONTENTS
  • I. INTRODUCTION
  • I.1 Background
  • I 2 Definitions and basic equations
  • I 3 Factors affecting sorption, diffusion and permeation
  • I.3.1 Nature of polymer
  • I.3.2 Molecular weight of the polymer
  • I.3.3 Nature of the penetrant
  • 1.3.3a.. Penetrant phase
  • 13.3.b, Pennant size and shape
  • I.3.4 Nature of additives in the polymer matrix
  • I.3.4.a.Plasticizers
  • I.3.4.b. Fillers
  • I.3.5 Temperature
  • I.4 Scope of the work
  • References
  • II. MATERIALS AND EXPERIMENTAL
  • II.1. Materials used
  • II.1.1 Natural rubber
  • Table 11.1. Specifications for ISNR-5 grade natural tubber.
  • II.1.2 Rubber chemicals
  • II.1.3 Fillers
  • Table 11.2. Characteristics of black fillers
  • II.1.4 Solvents
  • Table 11.3. Physical properties of solvents.
  • II.2 Preparation of rubber compounds
  • Table 11.4. Formulation of the mixes (phr)--
  • II.2.1 Compounding of mixes
  • II.2.2 Time of cure
  • II.2.3 Moulding of samples
  • Fig.11.1. Rheographs showing the curing of the samples to the commmon rheometric torque of 33.8 dNm
  • II.3 Sorption experiments
  • II.4 Pervaporation experiments
  • II.5 Tensile strength measurements
  • Fig. 11.2 Pervaporation apparatus
  • References
  • III. TRANSPORT OF AROMATIC HYDROCARBONS THROUGH CROSSLINKED NATURAL RUBBER
  • III.1 Results and discussion..
  • Table III.1. Values of degree of crcsslinking (v) x 10 5.
  • Fig.III.1. Mole per cent benzene uptake of natural rubber with different crosslinking systems at 280 C (The samples were cured to a torque of 33.8 dNrn)
  • Fig.III.2. Mole per cent toluene uptake of natural rubber with different crosslinking systems at 280C (Tho samples were cured to a torque of 33.8 dNm)
  • Fig.III.3. Structure of the networks formed by different vulcanization techniques
  • Table III.2. Values of bond length and bond energy.
  • Fig.III.4. Mole per cent rnesitylene uptake of natural rubber with different crosslinking systems, cured up to t90.
  • Fig.III.5. Mol per cent benzene uptake of CV system at different cure time.
  • Fig.III.6. Mole per cent solvent uptake of peroxide system at 28c
  • Fig.III.7. Dependence of maximum mole percent solvent uptake on molecular weight of the solvent
  • Table III.3. Values of swelling coefficient.
  • TableIII.4. Analysii of sorption data of NR+ aromatic hydrocarbons
  • Fig. III.8. Temperature dependence of mole per cent toluene uptake of CV system
  • References
  • IV. SORPTION AND DIFFUSION OF ALIPHATIC HYDROCARBONS INTO CROSS LINKED NATURAL RUBBER
  • IV.1 Results and discussion..
  • Fig. IV.1. Mole per cent n-hexane uptake of natural rubber with different crosslinking systems at 28°C (the samples were cured to the same rheometric torque of 33.8 dNm)
  • Fig. IV.2. Mole per cent n-nonane uptake of natural rubber with different crosslinking systems at 28°C (the samples were cured to the same rheometric torque of 33.8 dNrn)
  • Fig.IV.3. Mole per cent n-hexane uptake of natural rubber with different crosslinking systems cured up to t90 (Optimum cured)
  • Fig.IV.4. Mole per cent solvent uptake of peroxide system at 28°C.
  • Table IV.3. Values of diffusion coefficient
  • Fig.IV.5. The dependence of diffusion coefficient D on the number of carbon atoms of aliphatic hydrocarbons.
  • Fig.IV.6. Temperature dependence of mole per cent n-hexane uptake of DCP system.
  • Fig. IV.7. Arrhenius plots of log D* Vs I/T for NR with different crosslinking systems in n-hexane
  • References
  • V. INTERACTION OF CROSS LINKED NATURAL RUBBER WITH CHLORINATED HYDROCARBONS
  • V.1 Results and discussion..
  • Fig.V.1. Mole per cent CCl4 uptake of NR vulcanized by different systems (The samples were cured to a torque of 33.8 dNrn)
  • Fig. V.2. S-D-RS-RD curves of CV system.
  • Fig.V.3. S--D-RS-RD curves of DCP system
  • Fig.V.4. Mole per oent solvent uptake of CV system
  • Fig.V.5. Temperature dependence of mole per cent CCl4 uptake of CV system
  • Fig.V.6. Stress-strain curves of NR samples before swelling.
  • Fig.V.7. Stress-strain curves of NR samples after reaching equilibrium in CCl4.
  • Fig.V.8. Stress-strain curves of CV sample in different solvents.
  • Fig. V.9. Variation of tensile strength of NR samphs with exposure time in CCl4.
  • Fig.V.l0. Stress-strain curves of NR samples after a sorption-desorption cycle.
  • References
  • VI. TRANSPORT OF AROMATIC HYDROCARBONS THROUGH CARBON BLACK REINFORCED NATURAL RUBBER COMPOSITES
  • VI.I Results and discussion..
  • Fig.VI.1. Mole per cent benzene uptake of natural rubber with different fillers at 28c (The samples were cured to the optimum cure time)
  • Fig.V1.2. Mole per cent toluene uptake of natural rubber with different fillers 28°C (The samples were cured to the optimum cure time)
  • Fig.V1.3. Rheographs showing the curing of NR samples to the same torque (a) SAF, (b) ISAF, (c) HAF, (d) SRF.
  • Fig.V1.4. Mole per cent benzene uptake of natural rubber with different fillers cured to the same torque.
  • Fig.V1.5. Mole per cent benzene uptake of HAF filled natural rubber samples with different cure time.
  • Fig.V1.6. Dependence of Q, on the molecular weight of the solvents.
  • Table V1.2. Values of diffusion coefficient
  • Fig.V11.7. Dependence of modified diffusion coefficient on the particle size of fillers.
  • Table V1.3. Values of activation energy and interaction parameter
  • Fig. V1.8. Arrhenius pbts of log D Vs I/T for filled natural rubber samples +benzene.
  • Table V1.4. Thermodynamic functions AH, and AS
  • References
  • VII. EFFECT OF BLACK AND SILICA FILLERS ON LIQUID TRANSPORT THROUGH NATURAL RUBBER
  • VIl.I Results and discussion..
  • Fig.VII.l. Mole per cent benzene uptake for unfilled, black filled and silica filled NR, cured to t90 at 28C.
  • Table VII.l. Values of degree of crosslinking
  • Table VII.2 Analysis of sorption results of NR-solvent systems.
  • Fig. VII.2. Dependence of maximum equilibrium sorption value (Q, ) on cure time at 28°C.
  • Fig.VII.3. Mole per cent solvent uptake for black filled NR, cured to t90, at 28c
  • Table VII.3 Diffusion coefficients and permeation coefficients of NR-solvent system.
  • Fig.VII.4. Comparison between experimental and theoretical sorption curves for NR, cured to t90. in p-xylene (a) black (b) silica.
  • Fig.VII.5. Diffusion coefficient versus concentration for black filled and silica filled NR, with different cure time, in toluene at 28°C.
  • Fig. VII.6. Diffusion coefficient versus concentration for black filled and silica filled NR, cured to t90, in solvents at 28°C.
  • Fig. VII.7. Temperature dependence of mole per cent sorption for black filled NR cured to t90, in mesitylene.
  • Fig. VII.8. Temperature dependence of mole per cent sorption for silica filled NR cured to t90, in mesitylene.
  • Fig. VII.9. Dependence of diffusion coefficient on number of carbon atoms of aromatic hydrocarbons for NR cured to (a) t70 (b) and (c) t90 at 28, 50 and 70°C.
  • Fig. VII.10. Arrhenius plots of diffusivity for black filled and silica filled NR, cured to different cure time, in mesitylene.
  • Fig.VII.11. Arrhenius plots of diffusivity for black filled and silica filled NR, cured to t90 in solvents.
  • Fig.VII.12. Arrhenius plots of permeability for black filled and silica filled NR, cured to different cure time, in mesitylene.
  • Fig.VII.13. Arrhenius plots of permeability for black filled and silica filled NR, cured to t90 in solvents.
  • Table VII.4 Values of activation parameters
  • Table VII.5 Values of interaction parameter
  • References
  • VIII. SEPARATION OF ORGANIC LIQUID MIXTURES BY PERVAPORATION USING NATURAL RUBBER MEMBRANES
  • VIII.1 Results and discussion
  • VIII.1.l. Separation of aliphatic hydrocarbons/acetone mixtures
  • Fig.VIII.1. Variation of swelling ratio with the weight per cent of n-hexane in the feed.
  • Fig.VIII.2. Pervaporation performance of DCP membrane with n-hexane/acetone mixtures
  • Fig.VIII.3. Effect of vulcanizing systems on the permeation rate of n-hexanel/acetone mixtures of different compositions.
  • Fig.VIII.4. Effect of molecular weight of aliphatic hydrocarbons on the permeation rate through different membranes.
  • Fig. VIII.5. Variation of weight per cent of n-hexane in the feed with molecular weight of aliphatic hydrocarbons.
  • Fig.VIII.6. Effect of cure time on the permeation rate through NR membranes
  • Fig. VIII.7. Effect of cure time on the separation efficiency of NR membranes
  • Fig.VIII.8. Effect of membrane thickness on the pervaporation performance of NR membrane vulcanized by DCP.
  • VIll.1.2 Separation of chlorinated hydrocarbon / acetone mixtures
  • Fig.VIII.9. Variation of swelling ratio with weight per cent of CCl4 in the feed.
  • Fig.VIII.10. Effect of feed composition on the permeation rate of chlorinated hydrocarbons/acetone mixtures.
  • Fig.VIII.11.Weight per cent of chlorinated hydrocarbon in the permeate Vs that in the feed.
  • References
  • IX. CONCLUSION
  • APPENDIX I Future Outlook
  • APPENDIX II LIst of Publications
  • APPENDIX III Papers Presented In National / international Conferences
  • CURRICULUM VITAE