Biobased Filler Materials in Polymeric Composites: A Comprehensive Review of Epoxy and Polyurethane Systems

Polymeric composites, particularly epoxy and polyurethane systems, have gained significant attention due to their excellent mechanical, thermal, and chemical properties. However, the environmental concerns associated with petroleum-based polymers have driven research towards biobased alternatives. This review explores the integration of biobased filler materials derived from agricultural and marine waste into epoxy and polyurethane matrices to enhance their performance while promoting sustainability. The empirical review of epoxy and polyurethane resins reinforced with natural fillers highlights the significant role of bio-based additives in enhancing mechanical properties while promoting sustainability. Findings from reviewed studies demonstrate that natural fillers such as jute, sisal, lignin, and rice husk fish scales improve tensile strength, flexural strength, and wear resistance of polymer composites. However, excessive filler content can lead to agglomeration, reducing mechanical integrity. Optimal filler content varies depending on polymer type, with moderate concentrations yielding the best mechanical performance. Additionally, chemical modifications, such as silane treatment and alkalization, enhance filler-polymer adhesion, further improving material properties. Despite their advantages, challenges such as moisture sensitivity and long-term durability require further investigation.