Five networks based on a diglycidylether of bisphenol A-dimethacrylate prepolymer of molar mass 1 100 g em01 crosslinked with 35 % , 40 % , 45%, 50%, and 55% styrene mass fractions were characterized by Fourier transform infrared spectroscopy, cross-polarization/magic-angle spinning, nuclear magnetic resonance spectroscopy, styrene extraction, and rubber elasticity measurements. Various structural models were built up from the available analytical data, and their crosslink density was compared to the experimental data derived from rubber elastic moduli. Globally, network models based on a purely statistical approach but taking into account the incomplete cure conversion make it possible to predict the trends of modulus variations. The kinetic data on copolymerization show, however, that the material is diphasic, one phase being composed of the vinylester network and the other of practically pure polystyrene. We tried to take this heterogeneity into account in modulus predictions using a simple mixture rule, but the method failed for high styrene mass GANEM ET AL.fractions (s % 0.45), for which the experimental modulus value is about 50% higher than the predicted one. The results suggest the existence of a morphological transition for a critical styrene weight fraction between 40 % and 45 %.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.