Curing behaviour of compatible interpenetrating polymer networks based on epoxy and methacrylated epoxy

Abstract

Compatible interpenetrating polymer networks (IPNs) based on diglycidyl ether of bisphenol A (DGEBA) and methacrylated diglycidyl ether of bisphenol A (MADGEBA) in weight ratios of 100/0, 75/25, 50/50, 25/75 and 0/100 were blended and cured simultaneously by using dicumyl peroxide (DICUP) and hexahydrophthalic anhydride (HHPA) as curing agents. Fourier transform infrared spectroscopy (FTIR) was employed to investigate the intermolecular interactions and functional group changes. Viscosity increases during crosslinking were examined with a Brookfield viscometer. Curing exothermic peaks were studied with differential scanning calorimetry (DSC). The gel fractions of various IPN compositions were measured with a Soxhlet extractor. Samples thus prepared were checked for their compatibility by measuring glass transitions with DSC and damping peaks with rheometric dynamic spectroscopy (RDS). Experimental results revealed that good compatibility between components induced a network interlock, which subsequently resulted in incomplete cure of the IPN materials.