| Abstract: | Poly(vinylidene fluoride) exists in three crystalline forms. Optimum conditions for preparing form III were established by infrared spectroscopy, differential scanning calorimetry, and x-ray diffraction measurements. Form III is easily obtained by annealing mats of solution-grown crystals of form II at 175–185°C and is also preferentially formed by isothermal crystallization from the melt between 165 and 175°C. Below 165° crystallization of form II is favored. The melting point of form III is higher than that of form II. |
