Cassava Rhizome as a Bio-Filler in Epoxy Resin: A Study on Mechanical and Physical Properties

Growing concerns for the environment have sparked interest in natural filler reinforced composites. This research studied the effect of the particle size and amount of cassava rhizome on the properties of epoxy resin composites. A vacuum-assisted resin casting with a silicone rubber mold was used to prepare the composites. Cassava rhizome particles were classified into four size ranges: 105–149, 210–297, 297–420, and 420–590 µm and the concentrations were 10, 15, and 20 wt.%. Comprehensive analyses were conducted, including OM, FTIR, and SEM characterization, as well as mechanical evaluations such as tensile, impact, hardness, and three-point bending tests. In addition, bulk density and water absorption were performed. Results showed that the incorporation of cassava rhizome improved mechanical properties of the composites, such as hardness (Shore D), Young’s modulus, and flexural modulus, which increased by 25%, 36%, and 19%, respectively, compared to neat epoxy resin. On the other hand, impact strength, tensile strength, and elongation at break tended to decrease with increasing cassava rhizome amount. Although the incorporation of cassava rhizome initially reduced flexural strength, higher filler amounts showed a tendency to enhance it. As expected, smaller particle sizes yielded better mechanical properties of the composites. However, a higher amount of small-sized cassava rhizome also increased water absorption and bulk density.