ACETYLATION OF STARCH IN SUPERCRITICAL CO2

F. ARIAS DURÁN; D. E. DAMIANI; C. M. PIQUERAS

Ciudad Autonoma de Buenos Aires

Workshop; II Workshop Polímeros Biodegradables y Biocompuestos; 2015

ITPN- Universidad de Buenos Aires

Esterification of starch is a well known chemical modification to improve the gelatinization temperature, thermal stability and to reduce the tendency for retrogradation. Starch acetates are used as thickening agents in a variety of food products, as sizing agents for textile and as gummed tape adhesives. For most applications, relatively low degree of substitution (DS) products are required (0.01-0.2). Starch acetates are commonly produced in water, by using acetic anhydride (AAH) as substituent and NaOAc as catalyst. The OH of the starch is activated with the base to form a starch alkoxide (ST-O-) which subsequently will react with AAH to form the acetylated product and NaOAc. However, an undesired side reaction is the hydrolysis of AAH to form acetic acid. Supercritical CO2 (scCO2) is a green solvent which currently found several industrial applications in the polymers field. In this work, the acetylation of potato starch was performed in scCO2 medium in order to avoid side reactions and intensify the process production.