DIRECT CROSSLINKING PROCESS FOR PREPARING PERFLUOROALKYL-CROSS-LINKED FLUOROPOLYMER HAVING PERFLUOROETHER PENDANT GROUPS

摘要

This invention pertains to a novel thermal process for converting a fluoropolymer having cyano-functionalized perfluoroether pendant groups into a novel perfluoroalkyl-crosslinked fluoropolymer having perfluoroether pendant groups. The process comprises heating the fluoropolymer having cyano-functionalized perfluoroether pendant groups in the presence of Cl—F to a temperature in the range of 200 to 300° C. The fluoropolymer having cyano-functionalized perfluoroether pendant groups can first be formed into a shaped article, and the shaped article then subject to treatment in situ with Cl—F.

主权项

1. A process comprising forming a reaction mixture by combining, at a temperature in the range of room temperature to 100° C., Cl—F with a first cyano-functionalized polymer and a second cyano-functionalized polymer, each said cyano-functionalized polymer comprising a backbone chain, and wherein each said backbone chain comprises fluoroalkylene repeat units optionally substituted by ether oxygen, and a molar concentration in the range of a molar concentration of 0.5 to 50 mol-% of repeat units represented by Structure IIwhere x is an integer in the range of 0 to 3, y is an integer in the range of 0 to 6, and z is an integer in the range of 0 to 3; R1=(CF2)aCFR2, where a is an integer in the range of 0 to 6, and R2 is F or C1-6 perfluoroalkyl optionally substituted by ether oxygen; and R3 is F or C1-6 perfluoroalkyl optionally substituted by ether oxygen; with the proviso that y and z cannot both be zero; and, with the further proviso that no repeat unit in the backbone chain of said cyano-functionalized polymer has more than two vinyl hydrogens attached thereto; and, heating said reaction mixture to a temperature in the range of 250 to 300° C.; with the proviso that said first and second cyano-functionalized polymers can be the same or different.