Enzymatic degradation of poly(butylene succinate) with different molecular weights by cutinase.

Poly(butylene succinate) (PBS) films with different molecular weights were enzymatically degraded by cutinase. Changes in the properties of the films before and after enzymatic degradation were studied through scanning electron microscopy, differential scanning calorimetry, thermogravimetry, X-ray powder diffraction, proton nuclear magnetic resonance, and gel-permeation chromatography analysis. The weight loss of the films initially decreased and then increased with increasing molecular weight. Crystallinity was inversely proportional to weight loss and tended to decrease with prolonged degradation time. Crystalline and amorphous regions were simultaneously degraded. The thermal stability of PBS films decreased after enzymatic degradation. PBS was the main component of the enzymatically degraded polymers. The molecular weights of the films did not considerably change before and after degradation by cutinase.