Synthesis and Characterization of Bis(3-Vinyl Ester-2-Hydroxy Propane) Ether-Terminated Poly(Dimethylsiloxane) Toughened Epoxy-Clay Hybrid Nanocomposites

Abstract

A bis(3-vinyl ester-2-hydroxy propane) ether-terminated poly(dimethylsiloxane) (BVHPDMS), was synthesized from diglycidyl ether-terminated poly(dimethylsiloxane) and acrylic acid, and its structure was confirmed by FTIR, 1H and 13C NMR spectra. DGEBA epoxy resin was toughened with BVHPDMS using DDM as curing agent. The formation of BVHPDMS and its chemical reaction with epoxy resin was determined by FTIR. Epoxy and BVHPDMS toughened epoxy systems were further modified with organophilic montmorillonite clay. Organoclay filled hybrid BVHPDMS-epoxy resin castings were characterized for their thermal and mechanical properties. The introduction of 10% BVHPDMS into 5% organoclay filled epoxy resin improved the impact strength by 37.5% compared with unmodified epoxy resin system. The nanocomposites exhibited higher storage modulus (increased from 3060 to 3757 MPa) than unmodified epoxy resin. The presence of d001 reflections of the organophilic MMT clay in the XRD pattern of the cured product indicated the development of an intercalated clay structure. The heterogeneous morphologies of the BVHPDMS toughened epoxy and BVHPDMS toughened epoxy-clay hybrid systems were ascertained by SEM analysis.