Polyurethane-polystyrene interpenetrating polymer networks synthesized in the presence of a common solvent

Abstract

Interpenetrating polymer networks (IPN's) of polyurethane and polystyrene were synthesized by simultaneous polymerization. The effect of compositional variation and the presence of a common solvent in the reaction medium on the rate of polymerization, the onset of phase separation, and the morphology of product were investigated. 1,4-Dioxane was selected as a common solvent by the swelling experiment. The rate of network formation in the early stage of polymerization process increased with increasing the polyurethane composition. When 1,4-dioxane was present in the reaction medium, the extent of reaction of both components at the onset of phase separation was higher than that of IPN's by bulk preparation. The morphology of final product was influenced by the extent of reaction at the onset of phase separation. The density, glass transition behavior, and thermal stability were also studied.