Enhance interfacial properties of glass fiber/epoxy composites with environment-friendly water-based hybrid sizing agent

The interface improvement of fiber-reinforced composites has remained a vexing problem that limits the use of the excellent properties of fiber in composite applications. In this study, a novel water-based hybrid sizing agent was synthesized by in-situ generated silica within waterborne epoxy/waterborne epoxy curing agent system, which was used as a glass fiber (GF) surface modifier to enhance the interfacial properties of GF/epoxy (EP) composites. The morphology and wetting ability of GF after treated with the hybrid sizing agent, the single-GF tensile strength and the interfacial shear strength (IFSS) of the single-GF/EP composites were investigated. Experimental results showed that the wetting ability of GF and the IFSS of the single-GF/EP composites were significantly improved after being treated by the hybrid sizing agent. This work is aimed at developing an environment-friendly, safe, and effective water-based sizing for substituting the traditional solvent-based sizing.