Chapter 14 - Fluoropolymers, stable nitroxides and perfluoroalkylation

Abstract

An important breakthrough in the search for heat and fluid resistant elastomers to meet the demands of the aerospace industry was the discovery of DuPont's Viton® A in the mid-1950s. Its thermal stability was considerably lower than that of the raw elastomer owing to the nature of the curing reactions and the relative instability of the hydrocarbon-type crosslinks. Thus, improved cross-linking techniques were required. One method under consideration at the University of Manchester Institute of Science and Technology (UMIST) was to synthesize linear polymer chains incorporating units containing a pendant thermally-labile functional group (X). Kalathil C. Eapen undertook a postdoctoral assignment at the UMIST in 1969. As the project on the “self-curing” fluoroelastomers did not produce the hoped-for results, he decided to abandon it and start a new one. The first perfluorinated nitroxide to be isolated was the monooxyl (CF3)2NO·, known at UMIST as the “magic radical.” His work at Wright–Patterson Air Force Base (WPAFB), Ohio covered a variety of topics, including studies on both fluorinated and nonfluorinated materials.