PREDICTION AND ANALYSIS OF NONISOTHERMAL CRYSTALLIZATION OF POLYMERS

The crystallization behavior of polyetheretherketone (PEEK), polyoxyme thylene (POM), polyethyleneterephtalate (PET), and polypropylene (PP) under nonisothermal conditions has been studied; Differential scanning calorimetry was used to monitor crystallization from the melt and a k inetic model has been proposed to describe three-dimensional spherulit ic crystal growth. The model, which accounts for crystalline growth ra te, uses two modified Avrami equations to represent both heterogeneous and homogeneous nucleation and growth processes. The model parameters are all associated with physical constants. The predicted evolution o f absolute crystallinity showed good agreement with experimentally obt ained values for a wide range of cooling rates. (C) 1997 John Wiley & Sons.