Biocomposite based on rice husk silica and eugenol bio-epoxy resin: fabrication and mechanical characteristics

The bio epoxy resin was synthesized from eugenol, and its chemical structure was confirmed by proton NMR. Rice husk silica (SiO₂) was extracted from rice husk and used as an additive to fabricate full biocomposites with different contents in the range of 5 to 20 phr. The biocomposite samples based on bio-epoxy resin and rice husk silica were prepared at room temperature using an aliphatic amine hardener. The effects of rice husk silica on the characteristics of epoxy resin, such as activation energy, tensile strength, impact strength, and glass transition temperature, were examined in detail. The addition of silica to the epoxy resin resulted in improvements in their tensile strength, impact strength, and glass transition temperature (T_g), and reduction of activation energy of curing reaction. The bio epoxy resin in the presence of 15 phr silica exhibited better mechanical and thermal properties than other samples.