title: Enzymatic synthesis of poly(hydroxyalkanoates) in ionic liquids.
abstract: Ring-opening polymerization of five lactones catalyzed by Candida antarctica lipase B in ionic liquids yielded poly(hydroxyalkanoates) of moderate molecular weights up to Mn=13,000. In the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethane)-sulfonimide and with a low weight ratio of enzyme to lactone (1:100) we obtained polymers from beta-propiolactone, delta-valerolactone, and epsilon-caprolactone with degrees of polymerization as high as 170, 25, and 85, respectively; oligomers from beta-butyrolactone and gamma-butyrolactone with degrees of polymerization of 5; and a copolymer of beta-propiolactone and beta-butyrolactone with a degree of polymerization of 180. Water-immiscible ionic liquids were superior to water-miscible ionic liquids. Reducing the water content of the enzyme improved the degree of polymerization by as much as 50% for beta-propiolactone and epsilon-caprolactone.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, MN 55455, USA.
authors.forename: Johnathan T
authors.initials: JT
authors.lastname: Gorke
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Okrasa
authors.forename: Andrew
authors.initials: A
authors.lastname: Louwagie
authors.forename: Romas J
authors.initials: RJ
authors.lastname: Kazlauskas
authors.forename: Friedrich
authors.initials: F
authors.lastname: Srienc
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000737:chemistry / Q000378:metabolism; D002384:Catalysis; D004800:Enzymes, Immobilized / Q000378:metabolism; D004951:Esterification; D005656:Fungal Proteins; D052578:Ionic Liquids / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism*; D008970:Molecular Weight; D011091:Polyesters / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D012995:Solubility; D014631:Valerates / Q000378:metabolism; D000094122:Polyhydroxybutyrates
chemical_list: D020155:3-Hydroxybutyric Acid; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D052578:Ionic Liquids; D008049:Lipase; D011091:Polyesters; D054813:Polyhydroxyalkanoates; D014631:Valerates; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C431349:lipase B, Candida antarctica