Electrical conductivity enhancement in thermoplastic polyurethane-graphene nanoplatelet composites by stretch-release cycles

This study shows that electrical conductivity and elastic modulus of conductive thermoplastic elastomers containing graphene nanoplatelets (GnPs) can be significantly enhanced by exposing them to stretch-release cycles, without exceeding 20% of the maximum strain. Although no alignment of GnPs in any specific direction was detected, this enhancement was found to occur due to redistribution of the GnPs within the polymer matrix undergoing repeated stretch-release cycles. Up to 60% of reduction in electrical resistance and 30% enhancement in elastic modulus were measured for certain nanocomposites at the end of 1000 cycles. Processing of such GnP nanocomposites with stretch-release cycles could constitute an innovative approach to enhance their electrical and mechanical properties. Published by AIP Publishing.