Viscoelastic Properties of Mineral-Filled Poly(lactic acid) Composites

Poly(lactic acid) was filled with 20 wt% of the three mineral fillers Mica, Zeolite, and Vansil, differing in the particle shape and surface area. Viscoelastic properties of unfilled and filled composites were investigated via dynamic mechanical analysis, while filler and fracture surface morphology of the composites was analysed through scanning electron microscopy. Results demonstrate the relationships between viscoelastic damping behaviour of filled PLA composites and the filler distribution in the PLA matrix. Both damping reduction and scanning electron microscope analysis revealed that Zeolite was better distributed in the poly(lactic acid) matrix than the other used fillers Mica and Vansil. The interfacial filler/matrix adhesion has again proved to be the key factor determining thermal and mechanical properties of reinforced composite material.