Polymer Engineering and Science, Vol.37, No.11, 1825-1832, 1997
Crystallization of Syndiotactic Polystyrene
The crystallization of syndiotactic polystyrene (sPS) was studied over the temperature range from the glass transition (T-g) to the melting point (T-m). Using transmission electron and optical microscopies, the different lamellar and spherulitic microstructures which were formed over this temperature range were correlated with the measured crystallization kinetics. The late of crystallization was measured isothermally using thin samples in a. differential scanning calorimeter. The low temperature transformations were achieved by quenching first to the amorphous state, then reheating. The experimental measurements at both high and low temperatures of transformation could be closely fitted to the predicted rate constant. It was found that to estimate the crystallization parameters most accurately, the data must be fitted simultaneously at high and low temperatures and a relatively high value for the equilibrium melting temperature (561 K) must be used. The nonisothermal crystallization kinetics have been predicted from the isothermal experiments using Nakamura’s model in a manner similar to earlier work on other polymers.