MODIFIED AVRAMI EXPRESSION FOR POLYMER CRYSTALLIZATION KINETICS

The Avrami equation has been widely used to describe polymer crystallization kinetics. However, the equation accurately fits experimental data only during the early stages of the crystallization process, and is unsuccessful in describing the entire process because it does not take into account secondary crystallization. Here we present a modified Avrami expression that describes polymer crystallization kinetics that takes into account both primary and secondary processes. The expression uses a new parameter introduced to indicate the fraction of material that has completed crystallization when the primary crystallization process has terminated. The theoretical results are in good agreement with experimental data.