Lipase Catalyzed Synthesis and Characterization of Poly (Glycerol-Sebacate)
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Authors
Ning, Z.
Lang, K.
Xia, K.
Linhardt, Robert J.
Gross, R.
Issue Date
2022
Type
Article
Language
ENG
Keywords
Biology , Chemistry and chemical biology , Chemical and biological engineering , Biomedical engineering
Alternative Title
Abstract
This study demonstrated that immobilized Candida antarctica lipase B (N435) catalysis in bulk leads to higher molecular weight poly(glycerol sebacate), PGS, than self-catalyzed condensation polymerization. Since the glass-transition temperature, fragility, modulus, and strength for rubbery networks are inversely dependent on the concentration of chain ends, higher molecular weight PGS prepolymers will enable the preparation of cross-linked PGS matrices with unique mechanical properties. The evolution of molecular species during the prepolymerization step conducted at 120 °C for 24 h, prior to enzyme addition, revealed regular decreases in sebacic acid and glycerol-sebacate dimer with corresponding increases in oligomers with chain lengths from 3 to 7 units such that a homogeneous liquid substrate has resulted. At 67 h, for N435-catalyzed PGS synthesis, the carboxylic acid conversion reached 82% without formation of a gel fraction, and number-average molecular weight (Mn) and weight-average molecular weight (Mw) values reached 6000 and 59 400 g/mol, respectively. In contrast, self-catalyzed PGS condensation polymerizations required termination at 55 h to avoid gelation, reached 72% conversion, and Mn and Mw values of 2600 and 13 800 g/mol, respectively. We also report the extent that solvent fractionation can enrich PGS in higher molecular weight chains. The use of methanol as a nonsolvent increased Mn and Mw by 131.7 and 18.3%, respectively, and narrower dispersity (Đ) decreased by 47.7% relative to the nonfractionated product.
Description
Biomacromolecules, 23, 398-408
Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.
Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.
Full Citation
Lipase Catalyzed Synthesis and Characterization of Poly (Glycerol-Sebacate), Z. Ning, K. Lang, K. Xia, R. J. Linhardt, R. Gross, Biomacromolecules, 23, 398-408, 2022.