Novel Talc-Filled Biodegradable Bacterial Polyester Composites

Abstract

Talc-filled composites of a bacterial polyester, i.e., poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, were prepared by extrusion followed by an injection molding process. The effects of the talc weight content (15−50 wt %) on various mechanical and thermomechanical properties of the PHBV-based composites were studied. The tensile and flexural moduli of PHBV-based composites were improved by 70 and 166%, respectively, when reinforced with a talc content of 50 wt %. Theoretical predictions were used to compare the experimental tensile modulus values of talc-filled PHBV composites. Comparison of the experimental results with theoretical predictions predominantly favored a spherical geometry of the talc particles in the PHBV matrix rather than a platy morphology. The storage modulus (E‘) and heat deflection temperature (HDT) of the PHBV-based composites were found to increase when the composites were reinforced with talc particles. The coefficient of linear thermal expansion (CLTE) of PHBV was reduced by 56% for the composite reinforced with a talc content of 50 wt %. The filler orientation, filler dispersion, and filler−matrix adhesion were investigated by scanning electron microscopy (SEM).