Study of the crystallization of an aromatic poly-ether-ketone (PK99) by calorimetric and X-ray analysis

An analysis of the crystallization behaviour of a new poly(aryl-ether-ether -ketone-ketone), PK99, by differential scanning calorimetry (DSC) and wide- angle X-ray diffraction (WAXD) is presented. Isothermal crystallization TG were obtained in the whole range between the glass transition temperature ( T-g) and the melting temperature (T-m) as a consequence of the slow crystal lization kinetics stemming from the closeness of these transitions. The cal orimetric results, compared with WAXD data, were applied to determine the t heoretical melting temperature and crystallization enthalpy. The DSC and WA XD data were combined in order to calculate the total amount of the crystal lizable fraction of the polymer, and a model was proposed to explain the di fference between the fractions of crystallinity observed with these techniq ues. The thermal and X-ray data were also correlated with different lamella r morphologies arising from the crystallization conditions. Finally, DSC ex periments on the crystallized sample were used to detect the presence of a rigid amorphous phase which does not relax at T-g.