Determination of the parameters of crystallization of maleic anhydride modified polypropylene in model composites with glass fibres

Isothermal and nonisothermal crystallizations of maleic anhydride-modified iPP in glass fibres model composites with unsized and sized glass fibres were studied by differential scanning calorimetry (DSC), to evaluate the influence of glass fibres on crystallization behavior. Isothermal crystallization was followed in the temperature range from 391 K to 403 K, and the rate constant and Avrami exponents were determined. Nonisothermal crystallization was carried out at different cooling rates (1 -20 K/min). It was found that the crystallization kinetics of MAH-iPP was significantly altered in model composites. Decreased energy of formation of a nucleus with critical dimensions and decreased activation energy for nonisothermal crystallization were determined for the model composites with sized glass fibres, indicating faster growth of lamellae, in spite of model composite with unsized glass fibres