The influence of temperature, additives and polymorphic form on the kinetics of the phase transformations of copper phthalocyanine

The solid-state phase transformation of different polymorphic forms of copper phthalocyanine to the thermodynamically most stable β-modification was investigated so as to evaluate the influence of mixtures of different polymorphs and additives upon the order of the reaction from isothermal X-ray powder diffraction data. The data were analysed by sequential Rietveld refinement and the results evaluated using both Avrami and Arrhenius equations. The order of the reaction was significantly influenced by the availability of initially present β-copper phthalocyanine and both the nucleation rate and dimensionality of crystal growth depended strongly on sample composition and reaction temperature.