Synthesis and performance evaluation of polyurethane/silica hybrid resins

Purpose – The aim of this paper is to synthesise polyester/silica hybrid resins and their hybrid polyurethanes via in situ (IS) and blending (BL) methods and to evaluate the effect of preparation method, interaction type and silica content on the physico‐chemical and thermal properties of polyurethane/silica (PU/Silica) hybrid coatings.Design/methodology/approach – Silica particle‐containing silica sol was prepared according to Stober method using tetraethylorthosilicate as the precursor and then introduced into polyester matrix by in situ and direct blending method. The modified polyester/silica resin was further crosslinked with TMP‐TDI adduct to synthesise PU/Silica hybrid coatings and studied for thermo‐mechanical, physico‐chemical properties.Findings – It was found IS polymerisation caused more polyester segments to chemically bond onto the surface of silica particles than BL process. Results also reveal that due to stronger interaction between silica particles and PU matrix, hybrid resins prepared b...