Ionomer/ionomer thermoplastic IPNs based on poly(n‐butyl acrylate) and polystyrene

Abstract

AbstractThermoplastic interpenetrating polymer networks (IPNs) were prepared by combining poly(n‐butyl acrylate) with polystyrene, both polymers crosslinked independently with acrylic acid anhydride (AAA). Decrosslinking of both polymers was carried out by hydrolysis of the anhydride bonds. Neutralization of the carboxylic acid groups to form the ionomer was carried out in a Brabender Plasticorder. Two subclasses of thermoplastic IPNs were studied: (1) Chemically blended thermoplastic IPNs (CBT IPNs) were prepared by synthesizing polymer II in polymer I in a sequential synthesis; (2) mechanically blended thermoplastic IPNs (MBT IPNs) were prepared by melt blending separately synthesized polymers. Rheovibron characterization revealed that of the two combinations, the CBT IPNs were better mixed than the MBT IPNs. Investigations of phase continuity via melt viscosity and modulus suggest that the CBT IPNs have some degree of dual phase continuity. Transmission electron microscopy suggests dual phase continuity and relatively small phase domains, 2000–5000 Å for the CBT IPNs. The mechanical properties from tensile and Izod impact tests showed that the CBT IPNs were stronger than the MBT IPNs.