Characteristics of the Non-Isothermal and Isothermal Crystallization for the β Polymorph in PVDF by Fast Scanning Calorimetry

Structuring at very high rates has become one of the current and important topics of interest in polymer science, because this is a common protocol in the processing of films or fibers with industrial applicability. This work presents the study by fast scanning calorimetry, FSC, of poly(vinylidene fluoride), paying special attention to the conditions for obtaining the beta phase of this polymer, because it is the one technologically more interesting. The results indicate that this beta phase of poly(vinylidene fluoride) is obtained when the sample is isothermally crystallized at temperatures below 60 degrees C. Under non-isothermal conditions, the beta polymorph begins to be observed at rates above 400 degrees C/s, although a coexistence with the alpha modification is observed, so that exclusively the beta phase is obtained only at rates higher than 3000 degrees C/s.