| abstract |
A copolymer having tetrafluoroethylene units, hexafluoropropylene units, and units independently represented by formula in a range from 0.02 to 2 mole percent, based on the total amount of the copolymer. Rf is a linear or branched perfluoroalkyl group having from 1 to 8 carbon atoms and optionally interrupted by one or more -O- groups, z is 1 or 2, each n is independently from 1 to 6, and m is 0 or 1. The copolymer has a melt flow index in a range from 25 grams per 10 minutes to 35 grams per 10 minutes and has a combined number of unstable end groups and -CF 2 H end groups in a range from 25 per 10 6 carbon atoms up to 120 per 10 6 carbon atoms. The copolymer can be extruded to make articles, such as insulated cables. A method of making the copolymer is also disclosed. |