Abstract
R-lactide, a pivotal monomer for the production of poly (D-lactic acid) (PDLA) or stereocomplex poly (lactic acid) (PLA) was synthesized from alkyl (R)-lactate through a lipase-catalyzed reaction without racemization. From among several types of lipase, only lipase B from Candida antarctica (Novozym 435; CAL-B) was effective in the reaction that synthesized (R,. R)-lactide. Enantiopure (R,. R)-lactide, which consisted of over 99% enantiomeric excess, was synthesized from methyl (R)-lactate through CAL-B catalysis. Removal of the methanol by-product was critical to obtain a high level of lactide conversion. The (R,. R)-lactide yield was 56% in a reaction containing 100. mg of Novozym 435, 10. mM methyl (R)-lactate and 1500. mg of molecular sieve 5. A in methyl tert-butyl ether (MTBE). The important monomer (R,. R)-lactide that is required for the production of the widely recognized bio-plastic PDLA and the PLA stereocomplex can be obtained using this novel synthetic method.
Original language | English |
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Pages (from-to) | 201-207 |
Number of pages | 7 |
Journal | Journal of Biotechnology |
Volume | 168 |
Issue number | 2 |
DOIs | |
State | Published - Oct 2013 |
Keywords
- (R,R)-lactide
- Alkyl (R)-lactate
- Lipase
- Molecular sieve
- Novozym 435