Investigation of correlation between crystalline phase transition and lamellar morphorogy of vinylidene fluoride-trifluoroethylene copolymers by synchrotron DSC/WAXD/SAXS simultaneous measurements

Both of the crystalline forms I and II contribute to the ferroelectric phase transition for the Vinylidene fluoride-trifluoroethylene copolymer with VDF contents higher than 80 mol% The morphological change and its relation with the crystal structural change have not yet been clarified at all. We will report the experimental data concerning the simultaneous measurements of DSC/WAXD/SAXS during the heating and cooling process of VDF 82% copolymer samples. For the melt-quenched sample, the lamella formed with II form crystalline changed from II form to HT phase, and increase of a long period occurred a thickness of lamella at the same with a temperature rise. In the cooling process the lamella would be formed with I form crystalline and that formed with II form were observed.