Performance of Epoxy Resin Composites Reinforced with SiC Modified by Hydroxyl Silane Coupling Agents

Abstract To investigate the performance and underlying mechanism of epoxy resin composites reinforced with hydroxy silane‑treated silicon carbide (SiC), a novel hydroxy silane coupling agent was synthesized via a free‑radical reaction between hydroxyethyl methacrylate (HEMA) and γ‑mercaptopropyl trimethoxysilane (KH‑590), using 2,2′‑azobis(2‑methylpropionitrile) (AIBN) as the initiator. The freshly prepared coupling agent was then employed to functionalize SiC particles. Finally, these modified SiC particles were uniformly dispersed into an epoxy resin matrix to fabricate the SiC/EP composites, enabling subsequent evaluation of their mechanical and interfacial properties. Finally, the reinforcing mechanism of the hydroxy silane modified SiC in the epoxy matrix was analyzed. The results reveal that both hardness and flexural strength of the composites first increase and then decrease as SiC content rises; at 30 wt.% SiC loading, the composite attains its highest performance, with a hardness of 16.37 HV and a flexural strength of 4.64 MPa improvements of 69.29% and 76.74%, respectively, over the neat epoxy resin. Friction and wear tests demonstrated that the composite's tribological performance was significantly enhanced: at a SiC content of 30 wt.%, the friction coefficient and wear rate decreased by 23.68% and 74.56%, respectively, compared to the neat epoxy resin.