Preparation and Characterization of Arabinoxylan Esters

摘要

Arabinoxylan was isolated from corn fiber as a highly branched, water-soluble polysaccharide composed of xylose, arabinose, galactose, glucuronic acid and glucose. Treatment of this arabinoxylan with a C2-C4 aliphatic anhydride using methanesulfonic acid as a catalyst conveniently provided the corresponding arabinoxylan esters. The arabinoxylan esters were isolated as high molecular weight, amorphous solids with glass transition temperatures ranging from 61 to 138 °C. The glass transition temperatures were found to be highly dependent on the degree of substitution and upon the type of substituent. The arabinoxylan esters are thermally stable to near 200 °C but undergo significant and rapid thermal degradation when heated above the onset of thermal degradation.