Effect of Pyrolysis Derived Coconut Shell Biochar on the Mechanical, Thermal, Rheological, and Water Absorption Properties of PLA Composites

This study aims to develop sustainable PLA composites by incorporating coconut shell biochar (BC) (at 1, 2, 5 and 10 wt. %) and evaluating their mechanical, thermal, rheological, and water absorption performance. The composites exhibited enhanced tensile strength (21 to 68 MPa), hardness (28 to 53 HV), and flexural strength (a 62.5% increase), with crystallinity increasing from 24 to 47%. Thermal analysis revealed reduced stability but a 5% increase in char residue at 500 °C. Rheological improvements included higher storage/loss moduli and a 57% rise in damping factor. Water absorption increased with biochar content due to porosity and interfacial voids, confirmed by contact angle measurements. These results demonstrate the potential of PLA/BC composites as eco-friendly materials for packaging, agricultural films, and moisture-sensitive applications, contributing to sustainable development and greener urban environments.