Dynamic Properties of Filled Elastomers

Crosslinked rubber materials reinforced with nanofillers are important to many technologies and have a broad impact on the economy, climate and environmental sustainability, the most obvious being energy efficiency of tire technologies. Much of the work in this area is empirical and hence it has been difficult to a priori produce materials with tailored properties. Previous work in the group on polymer nanocomposite melts have shown that tuning parameters such as grafting density and the ratio of matrix to graft chain length results in various dispersion states, which in turn have a direct correlation with reinforcement. We extended the study to elastomers where we studied different morphologies. Linear tensile tests for the crosslinked state reveal that sparsely grafted nanoparticles with more particle-particle contact gives a significantly higher reinforcement whereas non-linear properties show very little dependence on the NP dispersion state. Proton MQ NMR spectroscopy method is used to measure the crosslink density of the composites. With an ultimate goal in mind to understand the reinforcement and hysteresis in rubber tires, we further aim to understand the conditions responsible behind it through the study of Payne effect.