Novel experimental protocol used to determine the nucleation kinetics of polymer realized by Flash DSC: The case of poly(L-lactic acid)/poly(D-lactic acid) blends

摘要

A novel experimental protocol used to determine the polymer nucleation kinetics has been proposed in this manuscript. As a supplementary of the existing FSC nucleation kinetics characterization methods, the nucleated sample was heated at a relative slower rate over an assigned temperature range, instead of directly heating the nucleated sample at fast heating or isothermal crystallizing the nucleated sample at higher temperature. And it was used upon that of the 20 kg/mol PLLA/PDLA blends. After heating the nucleated sample from 413 to 463 K at 0.5 K/s, the nucleus density of the sample had been reflected by the enthalpy of cold-crystallization, which equaled to the melting enthalpy measured by heating the sample at 2000 K/s. The validity of this novel experimental protocol was proved by comparing the nucleation kinetics of the PLLA/PDLA blends sample with the crystallization kinetics itself and the nucleation kinetics of HC measured by existing method.