A biodegradable crystalline aliphatic polyester, poly(butylenesuccinate) (PBS), and an amorphous semiaromatic nylon, poly(hexamethyleneisophthalamide-co-terephthalamide) (PA6IcoT), weremelted and reactively blended with p-toluene sulfonicacid as the catalyst. The isothermal and nonisothermal crystallizationprocesses of PBS and its blends with PA6IcoT were investigated bydifferential scanning calorimetry (DSC). Three different models (Jeziorny’s,Ozawa’s, and Mo et al.’s methods) were used to simulatethe isothermal and nonisothermal crystallization kinetics. Moreover,the crystalline morphologies were observed by polarized optical microscopy.The effects of PA6IcoT and the ester–amide exchange reactionbetween polyester and polyamide on the crystallization processes andcrystalline morphology are described in detail. [ABSTRACT FROM AUTHOR]