Synthesis and Characterization of Compound Coupling Agent-Modified Hollow Glass Microspheres/Epoxy Composites

In this study, hollow glass microsphere/epoxy composites modified with compound coupling agent of titanate (CS201) and silane (KH540) were prepared and characterized. The addition of the compound coupling agent improves the interfacial bonding between the microbeads and the resin matrix. Scanning electron microscopy results indicated that the compound coupling agent can effectively reduce the number of voids between the microbeads and the resin. FTIR and XPS spectra showed that new chemical bonds were formed between the hollow glass microspheres and resin, which enhanced the interfacial bonding between them. By testing the water absorption and mechanical properties of the composites, it found that the addition of the hybrid coupling agent can reduce the water absorption to a minimum level of 1.184%. Due to the improvement of interfacial compatibility, mechanical properties of the composites were enhanced, (with tensile strength of 43.03 MPa, bending strength of 44.56 MPa, bending modulus of 1407 MPa and compressive strength of 81.55 MPa). When the content of the coupling agent was 5% and the volume ratio of CS201 to KH540 was 1:1, the synergistic enhancement effect was the most significant.