PhD Defence – Kishor Kumar SADASIVUNI

Abstract: Elastomer Nanocomposites have a superior role in realizing the new generation smart materials. Because of the high modulus, durability, deformation extensibility and resilience required for technological applications, elastomers are reinforced with various kinds of macro, micro and nanofillers. Among these, nano fillers have attained wider attention due to their high aspect ratio, immense surface area and superior mechanical, electrical and gas barrier properties. The present thesis focus mainly on the fillers such as carbon Nanotubes, expanded graphite, graphene and clay reinforced poly (isobutylene-co-isoprene) rubber (IIR) composites with the aim of their applicability in fundamental research and technological fields. The usually faced problems of dispersion and interfacial interaction between the fillers and polymer during composite fabrication are addressed by studying the molecular level interactions taking place inside the material. For this dynamic measurements like stress relaxation, hysteresis, Payne Effect, and temperature modulated differential scanning calorimetry are used. When the graphene composite is applicable in making impermeable IIR membranes, CNT filled materials are fund to be useful as good sensing and dielectrics. Grafting of the chains with maleic anhydride enhances the interfacial interactions between clay and rubber chains and improves the mechanical properties. Finally this manuscript brings out tentative correlations between chain cooperative mobility in IIR nanocomposites and mechanical reinforcement.