title: Curdlan ester derivatives: synthesis, structure, and properties.
abstract: A series of ester derivatives of curdlan, which is a β-(1 → 3)-D-glucan extracellularly produced by microorganism, with varying alkyl chain lengths (C2-C12) were synthesized by the heterogeneous reaction using trifluoroacetic anhydride. As a result, high-molecular-weight (Mw ≥ 6 × 10(5)) and fully-acylated curdlan was obtained with relatively high yield (>70%). Thermal stability of curdlan was greatly improved by esterification. Crystallization was observed for curdlan esters with C2-C6 side chains. Both Tg (170 → 50 °C) and Tm (290 → 170 °C) of curdlan esters decreased with increasing the side-chain length. By the increase in the side-chain carbon number, curdlan esters showed lower Young's modulus and tensile strength, and larger elongation at break. Thus, material properties of curdlan esters can be controlled by changing the side-chain length. It was found that the increase of the side-chain length resulted in the decrease of crystallinity and the change of crystal structures.
authors: Science of Polymeric Materials, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors: Hironori
authors: H
authors: Marubayashi
authors: Science of Polymeric Materials, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors: Kazuyori
authors: K
authors: Yukinaka
authors: Science of Polymeric Materials, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors: Yukiko
authors: Y
authors: Enomoto-Rogers
authors: Science of Polymeric Materials, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors: Akio
authors: A
authors: Takemura
authors: Science of Polymeric Materials, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: atiwata@mail.ecc.u-tokyo.ac.jp.
authors: Tadahisa
authors: T
authors: Iwata
mesh_terms: D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D047071:beta-Glucans / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D004952:Esters; D047071:beta-Glucans; C038459:curdlan
keywords: Curdlan; Ester derivatives; Properties; Structure; Synthesis; β-(1→3)-d-Glucan