Abstract

Medium-chain-length polyhydroxyalkanoates (PHAmcl) are biodegradable and renewable biopolymers with elastomeric qualities. One commonly employed technique for enhancing the physical and mechanical properties of polymers is via the formation of composite materials by dispersion of fillers into the polymer matrix. We report on the preparation and characterization of composite materials using thermally reduced graphene (TRG) nanoparticles as filler with PHAmcl polymers. Results show that the addition of up to 2.5% (vol) graphene to PHAmcl increases the melting temperature by 1-3° C, the modulus by 200-590%, and the electrical conductivity by >7 orders of magnitude. Additionally, we use rheology and microscopy to characterize the composites. The results can be explained on the basis of polymer entanglement theory and the effects of polymer structure, filler loading volume, and the role of graphene-polymer interfacial forces.