Enzymatic synthesis of poly(ε-caprolactone): thermal properties, recovery, and reuse of lipase B from Candida antarctica immobilized on macroporous acrylic resin particles

摘要

Candida is a genus of yeast, and lipase B isolated from Candida antarctica (CALB) has been utilized as a biocatalyst for the synthesis of a variety of organic compounds including polyesters and polylactones. Among the various immobilization media reported in the literature, the porous acrylic resin utilized in Novozym-435 has been widely studied. Here, we report the enzyme recovery and reuse for the synthesis of poly(ε-caprolactone) in toluene at 70 °C for 4 h per cycle for up to 10 reaction cycles, which consistently resulted in polymers with a weight-average molecular weight, M_w, of ~ 50,000 g mol~(-1) and a polydispersity index of ~1.4. In addition, the thermal properties of the resin particles used in Novozym-435, with and without the enzyme, were evaluated by TGA and DSC analysis. The effect of mechanical agitation on the enzyme stability, recovery, and reuse was also discussed. These results may have significance to enzymatic polymer synthesis as well as to the enzyme immobilization on acrylic resins and other matrices.