Influence of carboxyl group on the acid hydrolysis of cellulose

Abstract

Cellulose isolated from wood is more susceptible than cotton cellulose to homogeneous hydrolysis in phosphoric acid. The influence of carboxyl group introduction at the C6 position on the hydrolysis rate of cellulose in 82.5% phosphoric acid was studied as a model of the oxidation of cellulose during pulping. The rate constant of hydrolysis for dissolving pulp was larger than that of cotton cellulose at temperatures of 25°-35°C. Mercerized cotton cellulose was partially oxidized regioselectively at the C6 position by a free radical system using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO). The oxidized cellulose was obtained at a range of 1.7-12.7mEq carboxyl content per 100g of cellulose. The hydrolysis rate of the oxidized cellulose samples accelerated with increasing carboxyl content in the samples. © The Japan Wood Research Society 2001.