F-19 NMR-STUDY OF THE MICROSTRUCTURE OF VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE COPOLYMERS

Copolymers of vinylidene fluoride (VDF) and trifluoroethylene (TRFE) covering the whole range of copolymer compositions were prepared by the bulk-polymerization method using a peroxide as initiator. The monomer reactivity ratios were ra(VDF)=0.7 and r (TRFE)=0.5. The microstructure of the copolymers was examined by high-resolution F NMR. The normalized monomer-diad and -triad fractions as a function of polymer composition were obtained from NMR line-intensity relationships and numerical calculations using the comonomer-sequence distribution theory suggested by Ito and Yamashita. It was found that the VDF–TRFE copolymer has a statistically random configuration, and the head-to-tail structures of VDF–TRFE or TRFE–VDF sequences are predominant. © 1979, The Society of Polymer Science, Japan. All rights reserved.