Polyisoprene silica nanocomposites and its structure property relationship*

Recently, tire companies have sought to improve their fuel economy to meet the demand for a higher fuel efficiency and environmental sustainability. To achieve this goal, tire technologies have looked to improving the tire rolling resistance. In this talk, we investigate the structure-property relationship of polymer grafted nanoparticles, where the grafted polymer provides a better control over the dispersion of the particles in a polymer matrix. The dispersion and resulting morphologies of various systems were studied and followed by rheology and dynamic mechanical testing to probe the impact of the various structures on the mechanical properties, in the melt and the crosslinked forms. Using small amplitude oscillatory shear, we found that increasing nanoparticle loading significantly contributed to mechanical reinforcement. Reduction in tan delta that accompanies this reinforcement indicates an improvement in rolling resistance. In addition, creep measurements help us to expand the frequency window of our study, allowing access to the lower frequencies that are relevant to the operating frequencies of a tire.