Abstract: The method for calculating kinetic crystallizability from the nonisothermal crystallization curves determined by using differential scanning calorimetry(DSC)has been investigated. A new equation was derived in terms of the differential equation for the nonisothermal crystallization. The kinetic crystallizability of polyethylene terephthalate containing different catalysts was calculated. The results indicate that the key to calculating the kinetic crystallizability lies in correctly selecting the temperature of maximum crystallization rate. The kinetic crystallizability obtained by this method gives the overall information of the polymer crystallization.

Key words: nonisothermal crystallization, kinetic crystallizability, DSC