To study the effect of enzymatic degradation on polymers morphology, the melt-crystallization experiments were performed. The samples were placed between a microscope slide and a cover slip on a heating table (THMS 600, Linkam Scientific Instruments LTD, England). The temperature was raised to 125°C for 5 minutes and a pressure of 250 g was applied to the cover slip. The samples were then cooled at a rate of 1°C/min to room temperature. Microscopic images were taken using a polarized-light microscope (Nikon Eclipse E600).