Effect of Fillers from Renewable Resources on the Performance of Novel Heat and Oil Resistant Thermoplastic Vulcanizates Based on Epoxidized Natural Rubber/Thermoplastic Polyurethane Blends

Thermoplastic vulcanizates (TPVs) based on thermoplastic polyurethane (TPU) and epoxidized natural rubber (ENR) were prepared by dynamic vulcanization. In this study, the influence of different types and loading levels of filler on the properties of ENR-25/TPU blends was investigated. Furthermore, a filler from renewable resources, namely Rice Husk Ash (RHA), and conventional silica were incorporated in the blends (i.e., premixed with ENR-25). Then, various loading levels of filler were investigated at 10, 20 and 30 phr and compared with the unfilled blend. It was found that the incorporation of filler into the blend results in higher complex viscosity, mechanical properties in terms of Young's modulus, tensile strength and hardness compared with the TPV without filler. The incorporation of ENR-25 into the blend shows lower hardness than pure TPU. It was also found that TPV filled with RHA revealed almost identical values for Young's modulus, tensile strength, elongation at break and hardness, than the same TPV filled with conventional silica. This indicates rice husk ash has great potential to be used as filler in polymer composites based on ENR/TPU blends.