Review: Polylactide Composites with Nanocarbon Fillers Obtained by Melt Mixing – Thermal and Electrical Conductivity

Polylactic acid (PLA) is a biodegradable polymer widely recognized for its renewable origin and biocompatibility, yet its low electrical and thermal conductivity limits advanced applications. Incorporation of carbon nanofillers such as graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) has proven effective in enhancing its functional performance. This review summarizes recent progress in the development of PLA-based conductive nanocomposites obtained by melt mixing processing. The mechanisms of electrical and thermal conduction are discussed with emphasis on percolation behavior, interfacial effects, and filler dispersion. While electrical conductivity improves by several orders of magnitude once a percolating network forms, thermal transport remains constrained by interfacial resistance. Hybrid systems combining CNTs and graphene show synergistic effects, achieving high conductivity at low filler contents. These materials demonstrate great potential for sustainable applications in electronics, heat management, and additive manufacturing.