A novel approach to interpenetrating networks of epoxy resin and polydimethylsiloxane

A novel methodology for preparing interpenetrating polymer networks (IPNs) between an epoxy resin, diglycidylether of bisphenol A (DGEBA) and polydimethylsiloxane (PDMS) was proposed. The vinyl-terminated PDMS (vinyl-PDMS) was partially crosslinked with hydrogen-containing PDMS (H-PDMS) and was mixed with DGEBA, modified silica (ai-silica), and a methyl tetrahydrophtalic anhydride (MTHPA) curing agent. Subsequently, the curing reactions of the DGEBA/m-silica and PDMS were allowed to occur separately and simultaneously leading to an IPN. The in-silica played a double-fold role: Cocuring with DGEBA and H-bonding with the oxygen atoms on the PDMS segments, and thus acted as a compatibilizer between DGEBA and PDMS and promoted the generation of the IPN structure. The resulted partially miscible structure was characterized through the dispersion of silica particles and the glass transition behavior of the samples. The mechanical properties of the IPNs were also investigated. (C) 2007 Wiley Periodicals, Inc.