【摘要】 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—CF₂—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﹏CF₂·或﹏CH₂·容易增长于CH₂=CF₂的CH₂端,而链自由基﹏CH₂·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。更多还原

【Abstract】 A series of VDF-TFE copolymers of different composition were studied by 56.4 MHz and 188.2 MHz high resolution 19F-NMR spectrometer. These results indicated that the chemical shifts of central -CF2- group are not only affected by the first and the second neighboring groups, but also by the third neighboring group. VDF and TFE seemed to copolymerize in a random way. The growing polymer chain radical -CF2. or-CH2 . is strongly favored over the CH2 end of CH2 = CF2, and the growth of the chain radical-CH2. trended towards CF2 = CF2 in the copolymerization of VDF and TFE.更多还原