Selective enzymatic degradation and porous morphology of poly(butylene succinate)/poly(lactic acid) blends

Poly(butylene succinate) (PBS) and poly(lactic acid) (PLA) were melt-blended in different proportions and selectively degraded by cutinase and proteinase K, respectively. The selective enzymatic degradation process was systematically investigated. The degraded PBS/PLA blends were analyzed via scanning electron microscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry. The results of the weight loss of PBS/PLA blends degraded by cutinase and proteinase K suggested that PLA hindered the cutinase-catalyzed degradation of PBS, whereas the addition of PBS in the blends accelerated the degradation of PLA within a specific PBS/PLA ratio. The change in crystallinity after degradation was closely related to the different way of degradation. The characterization of PBS/PLA blends after degradation showed that selective enzymatic degradation could not completely degrade PBS or PLA component. After degradation, the pores formed by proteinase K were more uniform and larger than those formed by cutinase. This work provides a new insight into the selective enzymatic degradation processes of the porous materials, which will be used in tissue engineering or oil-water separation in the future.