Functionalized Polycarbonate Derived from Tartaric Acid: Enzymatic Ring-Opening Polymerization of a Seven-Membered Cyclic Carbonate
Enantiomerically pure functional polycarbonate was synthesized from a novel seven-membered cyclic carbonate monomer derived from naturally occurring l-tartaric acid. The monomer was synthesized in three steps and screened for polymerization with four commercially available lipases from different sou...
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Published in | Biomacromolecules Vol. 9; no. 10; pp. 2921 - 2928 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
01.10.2008
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | Enantiomerically pure functional polycarbonate was synthesized from a novel seven-membered cyclic carbonate monomer derived from naturally occurring l-tartaric acid. The monomer was synthesized in three steps and screened for polymerization with four commercially available lipases from different sources at 80 °C, in bulk. The ring-opening polymerization (ROP) was affected by the source of the enzyme; the highest number-average molecular weight, M n = 15500 g/mol (PDI = 1.7; [α]D 20 = +77.8, T m = 58.8 °C) optically active polycarbonate was obtained with lipase Novozyme-435. The relationship between monomer conversion, reaction time, molecular weight, and molecular weight distribution were investigated for Novozyme-435 catalyzed ROP. Deprotection of the ketal groups was achieved with minimal polymer chain cleavage (M n = 10000 g/mol, PDI = 2.0) and resulted in optically pure polycarbonate ([α]D 20 = +56) bearing hydroxy functional groups. Deprotected poly(ITC) shows T m of 60.2 °C and ΔH f = 69.56 J/g and similar to that of the poly(ITC), a glass transition temperature was not found. The availability of the pendant hydroxyl group is expected to enhance the biodegradability of the polymer and serves in a variety of potential biomedical applications such as polymeric drug delivery systems. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1525-7797 1526-4602 |
DOI: | 10.1021/bm800696q |