A survey of dual phase continuity and miscibility in interpenetrating polymer networks, making use of selective decrosslinking and dissolution of one component: Poly(n‐butyl acrylate)/polystyrene

Abstract

AbstractA sequential interpenetrating polymer network, IPN, may be defined as a combination of two polymers in network form, at least one of which was polymerized or crosslinked in the presence of the other. Two major problems of interest to sequential IPN's relate to phase continuity and extent of mixing within each phase. A first attempt to define the molar volume of a network is made in terms of the molar volume of the polymer between crosslinks. This permits a thermodynamic calculation of the changes in molecular mixing expected as a function of crosslink density. The experimental system was poly(n‐butyl acrylate)/polystyrene IPN's, where the PnBA was crosslinked with acrylic acid anhydride. This last may be selectively hydrolyzed, forming a semi‐IPN, and then the PnBA can be extracted. Scanning electron microscopy and dynamic mechanical spectroscopy were carried out at each stage.