Mechanical and Electrical Behavior of PLA Composites with Various Carbon Black Concentrations

Abstract

Polylactic acid (PLA) is a promising biodegradable polymer with low carbon footprint, yet its brittleness and absence of electrical properties limit its applicability in functional contexts. To address these limitations, a study was done by incorporate recycled carbon black (CB) a sustainable and conductive filler into the PLA matrix at loading of 0,1,2 and 3 wt.%. The composites were produced using melt-mixing and 3D printing Fused Deposition Modeling (FDM), thereafter examining for mechanical, electrical and biodegradation properties. The result indicated that the recycled-CB markedly enhanced tensile strength, Young’s modulus, and hardness, with optimal reinforcement occurring at 2 wt.% due to efficient filler dispersion. Electrical conductivity exhibited a marked rise with the recycled CB content, where it reached a maximum at 3 wt.% due to the formation of percolation networks. Nevertheless, the increase in recycled-CB loading lowered the biodegradation rate by restricting water absorption and microbiological activity. The 2 wt% CB composites proved to be the optimal balance, providing robust mechanical properties, moderate conductivity and retained though slowed biodegradability. The finding of this study indicates that recycled CB can transform pure PLA into multifunctional material suitable for sustainable and biodegradable packaging for electrical while applying environmentally responsible engineering.