Enhanced Charpy impact strength of epoxy resin modified with vinyl-terminated polydimethylsiloxane

This article deals with enhancement of the toughness of epoxy resin (ER) based on diglycidyl ether bisfenol A by either polydimethylsiloxane (PDMS) or vinyl-terminated polydimethylsiloxane (VT-PDMS). To improve the compatibility of these two phases, dicumylperoxide (DCP) was used as a compatibilizer. It was established that only specific composition of the components can lead to enhancement of ER toughness without significant reduction of storage modulus, T-g, and interphase adhesion. The highest impact strength was recorded for ER with VT-PDMS (10 wt %) and DCP (2 wt %) due to increased interfacial compatibility between two phases, which was proved by H-1 NMR and dielectric spectroscopy. Critical ductile brittle transition occurring between 10 and 15 wt % of rubber was observed by both morphological and dynamic mechanical analysis studies. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45720.