Epoxy resin/POSS/chitosan‐modified silica nanocomposite: Characterization of thermal and mechanical properties

Abstract The present research investigated the properties of epoxy resin nanocomposites containing POSS and silica nanoparticles modified by chitosan and the effect of type and weight percent of nanoparticles on properties nanocomposites. The modification of silica by chitosan (CS) improved the mechanical and thermal performance of the nanocomposites, as evidenced by higher tensile strength, thermal stability, and ash content. At 1 wt.% of POSS, incorporation of 1 wt.% of silica resulted in the Young's modulus of 417 MPa, and the value of 717 MPa was obtained when 1 wt.% of CS was used. Also, At 1 wt.% of POSS, incorporation of 1 wt.% of silica resulted in the ash value of 9.48%, while incorporation of 1 wt.% of CS silica resulted in the ash value of 11.73%. The curing behavior of the nanocomposites was also influenced by the heating rate and the nanoparticle content. According to cure index calculations, all nanocomposite samples showed excellent cure. The nanocomposites exhibited increased hydrophobicity with higher polyhedral oligomeric silsesquioxanes (POSS) content, which could reduce the susceptibility to bacterial and microbial contamination. The morphology of the nanocomposites revealed that the modified silica improved the fracture toughness and the dispersion of the nanoparticles in the epoxy matrix. The results indicated that the surface modification of silica by chitosan could optimize the properties of the nanocomposites by adjusting the content of CS and POSS nanoparticles, and that the nanocomposite coatings could have potential applications in biomedicine. Highlights Silica nanoparticles were successfully modified by chitosan. Silica modification improved dispersion and distribution in the resin matrix. Nanoparticle modification improved mechanical properties at lower content. The presence of POSS increased contact angle from 60° to 81°. Thermal stability was successfully improved by the designed system.