title: Enzymatic Synthesis of a Bio-Based Copolyester from Poly(butylene succinate) and Poly((R)-3-hydroxybutyrate): Study of Reaction Parameters on the Transesterification Rate.
abstract: The enzyme-catalyzed synthesis of fully biobased poly(3-hydroxybutyrate-co-butylene succinate) (poly(HB-co-BS)) copolyesters is reported for the first time. Different Candida antarctica lipase B (CALB)-catalyzed copolyesters were produced in solution, via a one-step or a two-step process from 1,4-butanediol, diethyl succinate, and synthesized telechelic hydroxylated poly(3-hydroxybutyrate) oligomers (PHB-diol). The influence of the ester/hydroxyl functionality ratio, catalyst amount, PHB-diol oligomer chain length, hydroxybutyrate (HB) and butylene succinate (BS) contents, and the nature of the solvent were investigated. The two-step process allowed the synthesis of copolyesters of high molar masses (Mnup to 18 000 g/mol), compared to the one-step process (Mn∼ 8000 g/mol), without thermal degradation. The highest molar masses were obtained with diphenyl ether as solvent, compared with dibenzyl ether or anisole. During the two-step process, the transesterification rate between the HB and BS segments (i) increased with increasing amount of catalyst and decreasing molar mass of the PHB-diol oligomer, (ii) decreased when anisole was used as the solvent, and (iii) was not influenced by the HB/BS ratio. Tendencies toward block or random macromolecular architectures were observed as a function of the reaction time, the PHB-diol oligomer chain length, and the chosen solvent. Immobilized CALB-catalyzed copolyesters were thermally stable up to 200 °C. The crystalline structure of the poly(HB-co-BS) copolyesters depended on the HB/BS ratio and the average sequence length of the segments. The crystalline content, Tmand Tcdecreased with increasing HB content and the randomness of the copolymer structure.
authors.affiliation: BioTeam/ICPEES-ECPM, UMR CNRS 7515, Université de Strasbourg , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors.forename: Thibaud
authors.initials: T
authors.lastname: Debuissy
authors.affiliation: BioTeam/ICPEES-ECPM, UMR CNRS 7515, Université de Strasbourg , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Pollet
authors.affiliation: BioTeam/ICPEES-ECPM, UMR CNRS 7515, Université de Strasbourg , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Avérous
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D002384:Catalysis; D004951:Esterification; D005656:Fungal Proteins / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000737:chemistry*; D008049:Lipase / Q000378:metabolism*; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry; D013386:Succinates / Q000737:chemistry*; D013696:Temperature; D000094122:Polyhydroxybutyrates
chemical_list: D001672:Biocompatible Materials; D005656:Fungal Proteins; D006885:Hydroxybutyrates; D008049:Lipase; D011091:Polyesters; D013386:Succinates; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C431349:lipase B, Candida antarctica; C052819:diethyl succinate