Styrene Crosslinked Vinylesters I: Correlation between the Theoretical Structure and Some Thermophysical Properties

Six di or tetramethacrylates based on respectively bisphenol A diepoxides or phenol-epoxynovolacs were crosslinked by styrene in optimized conditions. Density, glass transition temperature, propagation rates of ultrasonic waves, tensile properties and rubbery modulus were then experimentally determined. A constitutive repeat unit of the network was written, on the basis of the hypothesis that the conversion of the styrene-methacrylate copolymerization was complete and that the resulting network was homogeneous. The relationships between the corresponding (theoretical) structure and the physical properties were then studied. Generally, the property values are in good agreement with theoretical predictions, except perhaps for tensile ultimate properties which appear lower than expected. It can be concluded that the true network structure is probably close to the ideal structure as assumed here.