Graphene Nanoplatelets or Polylactic Acid Conductive Polymer Composites: Tensile, Thermal and Electrical Properties

Conductive polymer composites (CPC) are gaining increasing popularity due to their unique characteristics, which include light weight and the ability to conduct electricity. In this work, CPC were prepared by blending the polylactic acid (PLA) with a conductive filler, graphene nanoplatelets (GNP), at dosages ranging from 1 to 12 wt % using an internal mixer. The hot press machine was used to compress the CPC into thin sheet, and subsequently characterized for tensile, thermal, and electrical properties. The results showed that the addition of GNP at 7 wt % (percolation threshold) successfully transformed the PLA into an electrically conductive material. The tensile modulus increased with added GNP, but elongation at break and tensile strength exhibited an opposite trend. The incorporation of GNP also enhanced the composite's thermal stability. The addition of GNP filler into an insulative PLA matrix, above the percolation threshold (7 wt %), has successfully developed a continuous conductive network. The electrons can move freely within the polymer matrix via the conductive pathways; thus, the material is now considered as conductive polymer composite. image