Crystalline forms in a copolymer of vinylidene fluoride and trifluoroethylene (52/48 mol %)

摘要: Abstract : The structure of 52/48 mol % copolymer vinylidene fluoride and trifluoroethylene has been investigated at various temperatures by X-ray diffraction. Melt-solidified samples consist a mixture two disordered crystalline phases, one trans-planar, the other 3/1-helical. Samples may be transformed to either phase appropriate means reveal hexagonal (or pseudo-hexagonal) molecular packing. all-trans obtained drawing or poling low temperatures; both treatments cause transformation phases into well-ordered planar zig-zag phase. Isolation 3/1-helical is achieved heating high temperatures, where-upon all samples, irrespective orientation polarization, undergo poorly ordered helical analogous that homopolymer; upon cooling, original, recovered. (Author)