Perfluoroelastomers, such as those described in U.S. Pat. Nos. 3,682,872, 4,281,092, 4,487,903 and 4,983,697, have properties that make them attractive for use under unusually severe conditions. These materials are suitable for applications requiring the characteristics of an elastomer and, at the same time, tolerance for exposure to high temperatures or to aggressive chemicals.
The mechanical properties of perfluoroelastomers, in common with other elastomers, are conventionally adjusted by varying the ratios of perfluoromonomers in the polymers, by varying the amount of carbon black and other compound ingredients, and by varying the curing or vulcanizing chemistry. Certain uses, however, require combinations of properties not attainable by known means. One particularly desirable improvement would be a reduction in glass transition temperature (T.sub.g) with the accompanying extension of service temperature range to lower temperatures.