| 摘要 |
1,231,333. Stabilized tetrafluoroethylene copolymers. E.I. DU PONT DE NEMOURS & CO. 26 March, 1969 [1 April, 1968], No. 15960/69. Heading C3P. A copolymer of tetrafluoroethylene and another ethylenically unsaturated fluorinesubstituted monomer in which, as measured by infra-red analysis, at least half of the end groups are of the formula and remaining end groups (if any) are radicals may be prepared by stabilizing such a copolymer having end groups of the formula by converting at least half of these end groups to methyl ester groups. In the examples tetrafluoroethylene, perfluoropropylperfluorovinyl ether and hexafluoropropylene are copolymerized in the presence of 1,2,2-trichloro-1,1,2- trifluoroethane, bis(perfluoropropionyl)peroxide water and ammonium persulphate and treated with methanol. |
