title: Two-step biocatalytic route to biobased functional polyesters from omega-carboxy fatty acids and diols.
abstract: Biobased omega-carboxy fatty acid monomers 1,18-cis-9-octadecenedioic, 1,22-cis-9-docosenedioic, and 1,18-cis-9,10-epoxy-octadecanedioic acids were synthesized in high conversion yields from oleic, erucic and epoxy stearic acids by whole-cell biotransformations catalyzed by C. tropicalis ATCC20962. Maximum volumetric yields in shake-flasks were 17.3, 14.2, and 19.1 g/L after 48 h conversion for oleic acid and 72 h conversions for erucic and epoxy stearic acids, respectively. Studies in fermentor with better control of pH and glucose feeding revealed that conversion of oleic acid to 1,18-cis-9-octadecenedioic acid by C. tropicalis ATCC20962 occurred with productivities up to 0.5 g/L/h. The conversion of omega-carboxy fatty acid monomers to polyesters was then studied using immobilized Candida antarctica Lipase B (N435) as catalyst. Polycondensations with diols were performed in bulk as well as in diphenyl ether. The retension of functionality from fatty acid, to omega-carboxy fatty acid monomer and to corresponding polyesters resulted in polymers with with unsaturated and epoxidized repeat units and M(w) values ranging from 25000 to 57000 g/mol. These functional groups along chains disrupted crystallization giving materials that are low melting (23-40 degrees C). In contrast, saturated polyesters prepared from 1,18-octadecanedioic acid and 1,8-octanediol have correspondingly higher melting transitions (88 degrees C). TGA results indicated that all synthesized polyesters showed high thermal stabilities. Thus, the preparation of functional monomers from C. tropicalis omega-oxidation of fatty acids provides a wide range of new monomer building blocks to construct functional polymers.
authors.affiliation: NSF I/UCRC for Biocatalysis and Bioprocessing of Macromolecules, Department of Chemical and Biological Sciences, Polytechnic Institute of NYU, Six Metrotech Center, Brooklyn, New York 11201, USA.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Yang
authors.forename: Wenhua
authors.initials: W
authors.lastname: Lu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Wenchun
authors.initials: W
authors.lastname: Xie
authors.forename: Minmin
authors.initials: M
authors.lastname: Cai
authors.forename: Richard A
authors.initials: RA
authors.lastname: Gross
mesh_terms: D055162:Biocatalysis; D002152:Calorimetry, Differential Scanning; D002175:Candida / Q000201:enzymology; D004800:Enzymes, Immobilized / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry*; D005285:Fermentation; D005656:Fungal Proteins; D006838:Hydrocarbons / Q000737:chemistry*; D008049:Lipase / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D005227:Fatty Acids; D005656:Fungal Proteins; D006838:Hydrocarbons; D011091:Polyesters; D011108:Polymers; D008049:Lipase; C431349:lipase B, Candida antarctica