Enzymatic Synthesis of Poly(alkylene succinate)s: Influence of Reaction Conditions

Application of lipases (preferentially Candida antarctica Lipase B, CALB) for melt polycondensation aliphatic polyesters by transesterification activated dicarboxylic acids with diols allows to displace toxic metal and oxide catalysts. Immobilization the enzyme enhances activity temperature range use. The possibility use enzyme-catalyzed in is studied compared results polycondensations solution. experiments show that CALB successfully catalyzes both, divinyladipate dimethylsuccinate, respectively, 1,4-butanediol. NMR spectroscopy, relative molar masses obtained size exclusion chromatography, MALDI-TOF MS wide-angle X-ray scattering are employed compare influence synthesis conditions poly(butylene adipate) (PBA) succinate) (PBS). It shown enzymatic immobilized deviates influences mass. CALB-catalyzed PBA solution 24 h at 70 °C achieves up Mw~60,000 g/mol, higher than reported previously comparable conventional PBA, while resulted a moderate decrease mass Mw~31,000. Enzymatically catalyzed PBS yields Mw~23,400 g/mol vs. Mw~40,000 titanium(IV)n-butoxide. Melt catalysis reduce reaction time from days 3–4 h.