Polylactide/Graphene Nanoplatelet Composites for Advanced Functional Applications

ABSTRACT This study investigates the structure–property relationships of polylactide (PLA) nanocomposites containing graphene nanoplatelets (GNP) and trimellitic anhydride‐modified GNPs (TMA‐GNP). Surface modification of the GNPs with TMA improved the physical interfacial interactions between the GNPs and the PLA matrix, resulting in improved dispersion of the tactoids in the PLA/TMA‐GNP composites. The electrical percolation was lower for the PLA/GNP composites (2.7 wt%) compared to the PLA/TMA‐GNP composites (5.2 wt%), whereas the rheological percolation was similar at 7.5 wt%. Both systems reached similar maximum electrical conductivity (~0.2 S/m) and thermal conductivity (~1 W/m K) at 30 wt% loading. The addition of GNPs significantly increased the relative real permittivity, with maximum values of 10 at 30 GHz. The platelet‐like GNPs acted as nucleating agents, increasing the crystallization temperature and enhancing the crystallinity of PLA. Mechanical testing revealed substantial improvements in the flexural modulus, while impact strength increased up to intermediate GNP concentration before decreasing at higher contents due to aggregation. The results demonstrate that GNP surface modification and loading can be tuned to tailor the multifunctional electrical, thermal, and dielectric properties of PLA‐based nanocomposites for advanced electronic applications.