| abstract |
A vulcanizable fluorelastomer having advantages over known fluoroelastomers for many applications can be prepared by copolymerizing A. about 50-65 mole percent of tetrafluoroethylene, B. about 5-26 mole percent of vinylidene fluoride and C. about 20-45 mole percent of at least one olefin component selected from the group: (1) propylene, (2) butene-1, (3) a mixture of about 0.1-50 mole percent of ethylene or isobutylene and about 50-99.9 mole percent of propylene or butene-1, and (4) a mixture of about 50 mole percent of ethylene and 50 mole percent of isobutylene. |