Enhanced thermal, mechanical and electromagnetic interference shielding properties of graphene nanoplatelets-reinforced poly(lactic acid)/poly(ethylene oxide) nanocomposites

Abstract Graphene nanoplatelets (GNPs) were studied as a novel nanofiller of miscible poly(lactic acid) (PLA)/poly(ethylene oxide) (PEO) blend matrix. The adding level of GNPs varied from 0 to 15 wt%. PLA was blended with PEO to enhance its flexibility, while further incorporation of GNPs was aimed at improving the rigidity, thermal stability and electromagnetic interference (EMI) shielding properties of PLA/PEO blends. Rheological results and scanning electron micrographs revealed that a percolating 3-dimesional network within the PLA/PEO matrix was formed when the GNPs content above 6 wt%. The addition of 15 wt% GNPs into PLA/PEO matrix led to an increase of 247% and 83% in tensile modulus and strength, respectively, while the elongation at break was still at an acceptable value of 82.1%. Moreover, the initial degradation temperature (Td5) increased by 31.9 °C. In addition, the incorporation of GNPs enhanced significantly the EMI shielding effectiveness (SE) of PLA/PEO blend matrix. Compared with PLA/PEO nanocomposites with 6 wt% GNPs, further addition of 1 wt% carbon nanotubes (CNTs) improved remarkably the thermal, mechanical, electricity and EMI SE of the materials. The effect of PEO and nanofillers on the crystallization behavior of PLA was also addressed.