Synthesis and characterization of alginic acid ester derivatives

Yusuke Matsumoto; Daisuke Ishii; Tadahisa Iwata

doi:10.1016/j.carbpol.2017.05.001

Synthesis and characterization of alginic acid ester derivatives

Carbohydr Polym. 2017 Sep 1:171:229-235. doi: 10.1016/j.carbpol.2017.05.001. Epub 2017 May 2.

Authors

Yusuke Matsumoto¹, Daisuke Ishii², Tadahisa Iwata³

Affiliations

¹ 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.
² Macromolecular Biochemistry Laboratory, Department of Chemistry for Life Science and Agriculture, Faculty of Life Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.
³ 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.

PMID: 28578958
DOI: 10.1016/j.carbpol.2017.05.001

Abstract

Esters derivatives of alginic acid (Alg) were prepared in carboxylic acid/carboxylic acid anhydrides system by using aqueous perchloric acid as the catalyst. Degree of substitution of hydroxyl group of Alg was estimated to be 2, showing that the hydroxyl group of Alg was fully esterified. Alg acid esters showed the solubility to common organic solvents such as acetone and chloroform. In particular, alginic acid hexanoate formed self-standing solvent-cast film, although the film showed brittle mechanical behavior. Furthermore, Alg esters showed glass transition temperature (T_g) in a temperature range between 100 and 200°C, that is in the same range as the conventional synthetic amorphous polymers. It was also shown that the T_g gradually lowered with the increasing acyl side chain length. These results show that Alg esters are plastic materials with tunable organosolubility and thermal properties.

Keywords: Alginic acid; Ester derivatives; Solubility; Thermoplastics.