A high‐performance fluorocarbon elastomer

Abstract

Abstract Perfluorinated elastomeric copolymers of tetrafluoroethylene and perfluoro(methyl vinyl ether), containing 20–50 mole‐% of the vinyl ether moiety, were prepared in aqueous emulsion free radical initiated polymerization systems. The two monomers show sufficiently similar relative reactivity ratios to permit the preparation of homogeneous copolymers at high monomer conversions. Detailed properies of a 65/35 (molar) copolymer, including outstanding fluid and chemical resistance, to aqueous media and to nearly all organic and inorganic fluids, excellent thermal and oxidative stability, and very low permeability, are given. Efforts to vulcanize the copolymer to achieve good mechanical properties over a wide temperature range were not particularly successful. Through the incorporation of an unspecified cure site monomer, vulcanizates showing to a large degree the desirable properties of the raw copolymer along with good stress‐strain properties and compression set resistance have been obtained.