Structural effects upon enzymatic hydrolysis of poly(butylene succinate-co-ethylene succinate)s

High molecular weight poly(butylene succinate-co-ethylene succinate)s, P(BS-co-ES)s, were obtained from succinic acid, 1,4-butanediol, and/or ethylene glycol through a polycondensation process. Enzymatic hydrolysis of hot-pressed copolyester films was carried out by utilizing lipases derived from a wide variety of microorganisms. The formation of water-soluble total organic carbon (TOC) was monitored to determine the effect of structure upon enzymatic degradability. The P(BS-co-ES) copolyester containing approximately 53 mol % ES exhibited a minimum in systemic crystallinity and a maximum in enzymatic degradation. These results suggest that the degree of crystallinity may be the dominant influence upon the rate of degradation. Furthermore, it appears that the sequence distribution of BS and ES subunits has little effect upon lipase activity.