Benzoxazine Copolymers with Mono- and Difunctional Epoxy Active Diluents with Enhanced Tackiness and Reduced Viscosity

Abstract

The influence of epoxy active diluents, 1,4-butanediol diglycidyl ether (BD) and furfuryl glycidyl ether (FUR), in the mixtures with benzoxazine monomer based on bisphenol A, formaldehyde and m-toluidine (BA-mt), on the properties of a matrix was disclosed in this work. Resins were modified to achieve good tackiness at room temperature and reduced viscosity. The influence of mono- and difunctional modifiers on the process of curing was studied by way of differential scanning calorimetry and oscillatory rheology. The addition of BD and FUR shifted the curing peak to higher temperatures and significantly reduced viscosity. Preferable tackiness at ambient temperature was achieved with 10 phr of epoxy components in mixtures. However, cured blends with difunctional epoxy BD had an advantage over monofunctional FUR in enhanced tensile strength with remaining glass transition temperature at the level of neat benzoxazine (217 °C).