Crystallization kinetics in blends of poly-?-caprolactone and poly(styrene-ran-acrylonitrile)

The overall crystallization process in blends of poly-?-caprolactone (PCL) and poly(styrene-ran-acrylonitrile) (SAN) has been studied as a function of temperature and blend composition. The spherulitic growth rates turned out to be independent of time even at high crystallization temperatures and high SAN content. Addition of SAN slowed down the growth rate at a given crystallization temperature. Secondary nucleation analysis of the growth rates provided values of the average surface free energy (??6)1/2. It was found that this function decreased slightly with increasing SAN content. The crystallization isotherms were analyzed in terms of the Avrami equation. The Avrami exponent was found to be the same, n = 3, for all blends.