TRANSPARENT FLUOROCARBON-BASED SEMI-II IPN ELASTOMERS BY HIGH-ENERGY RADIATION METHODS

Semi‐II interpenetrating polymer network fluorocarbon elastomers were prepared by the addition of small amounts of a multifunctional monomer to the linear fluorocarbon polymer, followed by radiation polymerization in situ. The linear fluorocarbon is physically bound up with crosslinked network II, producing a semi‐IPN of the second kind. Due to the high‐energy radiation attack on the fluorocarbon backbone, a significant amount of graft copolymer forms which improves compatibility and yields clear, transparent elastomers. High‐energy β and γ radiation produce very similar semi‐IPN elastomers. Low‐energy UV, which does not promote grafting, produces poorer quality elastomers which show significantly less optical clarity, much lower strength, and higher creep. High‐energy radiation also appears to destroy possible incipient crystallinity thought to be present in the linear fluorocarbon material. Copyright © 1979 John Wiley & Sons, Inc.