title: Effect of comonomer-unit compositional distribution on thermal and crystallization behavior of bacterial poly[(3-hydroxybutyrate)-co-(3-mercaptopropionate)].
abstract: The physical properties of novel sulfur-containing biopolymers, poly[(3-hydroxybutyrate)-co-(3-mercaptopropionate)]s [P(3HB-co-3MP)s], have been investigated in detail by(1)H and (13)C NMR spectroscopy, wide-angle X-ray diffraction (WAXD) analysis, DSC, and FT-IR spectroscopy. Based on a solvent/non-solvent (chloroform/heptane) fractionation method, an original P(3HB-co-3MP) sample with 3MP unit content of 16.3 mol-% was fractionated into eight fractions with 3MP unit content ranging from 10.3 to 37.2 mol-% and number-average molecular weight from 0.4 x 10(5) to 2.9 x 10(5). The thermal and crystallization behavior were found to be greatly affected by the comonomer-unit composition and its distribution. Furthermore, the 3MP comonomer unit was found to be included in the crystalline phase in some fractions.
authors.affiliation: Department of Biomolecular Engineering, Tokyo Institute of Technology, Nagatsuta 4259-B-55, Midori-ku, Yokohama 226-8501, Japan.
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.forename: Tungalag
authors.initials: T
authors.lastname: Dong
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000737:chemistry*; D015097:3-Mercaptopropionic Acid / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D005591:Chemical Fractionation; D003460:Crystallization; D009682:Magnetic Resonance Spectroscopy; D011108:Polymers / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D011108:Polymers; D015097:3-Mercaptopropionic Acid; D020155:3-Hydroxybutyric Acid