SIMULATION OF CRYSTALLIZATION KINETICS AND MORPHOLOGICAL DEVELOPMENT DURING ISOTHERMAL CRYSTALLIZATION OF POLYMERS: EFFECT OF NUMBER OF NUCLEI AND GROWTH RATE

The effect of number of nuclei and growth rate on crystallization kinetics and detailed morphological development during isothermal crystallization of a polymer was investigated using a stochastic simulation. The results show that number of nuclei significantly affects both crystallization kinetics and polymer morphology. An increase in the number of nuclei hastens the crystallization process by speeding up the impingement phenomenon and increasing the levels of impingement. Growth rate has a stronger impact on crystallization kinetics, but it only helps speed up the impingement phenomenon without increasing the level of impingement. Although growth rate influences an average spherulite size and distribution of spherulite size during crystallization, it has no effect on final morphology. The quantitative understanding of morphological development obtained from this work will be a key element for constructing quantitative morphology-property relationships.     

Stochastic simulation for morphological development during the isothermal crystallization of semicrystalline polymers: A case study of syndiotactic polypropylene

A stochastic simulation scheme for predicting morphological development during nucleation and subsequent crystal growth based on predetermined crystallization kinetic data of a semicrystalline polymer under quiescent isothermal conditions is proposed. Based on previously obtained crystallization kinetic data for syndiotactic polypropylene (s‐PP) used as the input information, the simulation scheme was successful in predicting the morphological development of s‐PP during isothermal crystallization from the melt state. The predicted development of crystallinity during crystallization was reanalyzed with the Avrami macrokinetic model, and good agreement between the predicted and theoretical values for s‐PP was observed. On the basis of this simulation scheme, both the spherulite size and its distribution during the course of crystallization could also be predicted. Although the spherulitic growth rate influenced both the spherulite size and its distribution during the course of crystallization, it had no effect on the final spherulitic morphology or the resulting average spherulitic size. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009