Effectiveness of different immobilized Candida antarctica lipase b (iCaLB) in the production of biobased oligoester derivatives from poly(butylene succinate) (PBS) and poly(butylene adipate) (PBA)

The use of lipases (Candida antarctica Lipase B, CaLB) immobilized on different solid supports for the preparation of biodegradable aliphatic polyesters poly(butylene adipate) (PBA) and poly(butylene succinate) (PBS) by esterification of unactivated dicarboxylic acids with 1,4-butanediol is presented. The immobilization of CaLB through absorption or a covalent attachment to different solid supports enhances their use as a catalyst for polycondensation reactions both in solution and in bulk. The results indicated that the different immobilized CaLBs were able to catalyze succesfully the polycondensation of both succinic and adipic acid with 1,4-butanediol, yielding the linear aliphatic polyesters PBS and PBA, respectively, by using a two-step polymerization process. Techniques such as nuclear magnetic resonance (NMR), relative molar mass obtained by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) were applied to compare the influence of the solid support on the obtention of PBA and PBS. Herein, it is shown that the nature of the solid support employed on each immobilized CaLB enzyme modifies the activity and effectivity towards polycondensation of PBA and PBS having a strong influence on the molecular weights and crystallinity.