PREDICTION OF POLY(OXYMETHYLENE) NONISOTHERMAL CRYSTALLIZATION BEHAVIOR FROM ISOTHERMAL DATA

The spherulite growth, nucleation-related, Kg, parameter values obtain ed from isothermal data by DSC or optical microscopy) and two other ad justable parameters (the spherulite growth rate preexponential factor and the Avrami's or Tobin's exponent, n) have been used with Nakamura' s and Tobin's modified non-isothermal equations, to model the kinetics of polymer non-isothermal crystallization. Malkin's model was also te sted, for comparison. It is shown that, for polymers that crystallize on cooling almost entirely at temperatures higher than the maximum gro wth rate temperature, this Tobin's-like non-isothermal model accuratel y describes the experimental behaviour with only 2 parameters.