title: Ultrasound assisted lipase catalyzed synthesis of poly-6-hydroxyhexanoate.
abstract: Ultrasonic irradiation greatly improved the Candida antarctica lipase B mediated ring opening polymerization of ε-caprolactone to poly-6-hydroxyhexanoate in the ionic liquid 1-ethyl-3-methylimidazolium tetraflouroborate. Compared to the conventional nonsonicated reaction, sonication improved the monomer conversion by 63% and afforded a polymer product of a narrower molecular weight distribution and a higher degree of crystallinity. Under sonication, the polydispersity index of the product was ~1.44 compared to a value of ~2.55 for the product of the conventional reaction. With sonication, nearly 75% of the monomer was converted to product, but the conversion was only ~16% for the reaction carried out conventionally. Compared to conventional operation, sonication enhanced the rate of polymer propagation by >2-fold and the turnover number of the lipase by >3-fold.
authors: Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors: A M
authors: AM
authors: Gumel
authors: M S M
authors: MS
authors: Annuar
authors: Y
authors: Y
authors: Chisti
authors: T
authors: T
authors: Heidelberg
mesh_terms: D002384:Catalysis / Q000528:radiation effects; D004789:Enzyme Activation / Q000528:radiation effects; D019220:High-Energy Shock Waves; D008049:Lipase / Q000737:chemistry* / Q000528:radiation effects*; D011091:Polyesters / Q000737:chemistry* / Q000528:radiation effects*; D011108:Polymers / Q000138:chemical synthesis* / Q000528:radiation effects*; D011829:Radiation Dosage; D013010:Sonication / Q000379:methods*
chemical_list: D011091:Polyesters; D011108:Polymers; C111948:poly(hydroxyethanoate); C016240:polycaprolactone; D008049:Lipase