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应用高分辨率核磁共振仪研究了一系列不同组成的偏氟乙烯和四氟乙烯共聚物。指出,共振核—CF_2—的化学位移不仅受第一、二邻位基团的影响,也受第三邻位的影响。偏氟乙烯和四氟乙烯以无规共聚进行反应,在共聚反应中的链自由基﹏CF_2·或﹏CH_2·容易增长于CH_2=CF_2的CH_2端,而链自由基﹏CH_2·在偏氟乙烯和四氟乙烯共聚反应中的增长倾向于四氟乙烯。
A series of copolymers of vinylidene fluoride and tetrafluoroethylene with different compositions were studied by high resolution NMR. It is pointed out that the chemical shift of the resonant nucleus -CF 2 - is affected not only by the first and the second ortho groups but also by the third ortho position. Vinylidene fluoride and tetrafluoroethylene random copolymerization reaction, in the copolymerization reaction chain radical ﹏CF_2 · or ﹏CH_2 · easy to grow in CH_2 = CF_2 CH_2 end, while the chain free radical ﹏CH_2 · in vinylidene fluoride And tetrafluoroethylene copolymerization reaction tends to tetrafluoroethylene.