Results of the variation of crystallinity with heat treatment are shown in Figs. 2 and 3. Tables 2 and 3 report the influence of heat treatment on spherulite size. From the results, it can be seen that, with an increase in temperature in the heat treatment, the
crystallinity increased; with an increase in the time of the heat treatment, the crystallinity also went up, and tended towards stabilization. The process of heat treatment did not affect the spherulite size of the materials see Tables 2 and 3. because it only increases the integrity of the materials and the spherulithic growth speed does not vary throughout the process.