Thermal degradation of cellulose esters and their tosylated products in air

Abstract

The thermal decomposition behaviour of cellulose, its acetate and benzoate esters and their tosylates in static air have been studied by differential scanning calorimetry and thermogravimetry from ambient temperature to 450°C. The various reactions involved, viz. dehydration, deacetylation, debenzoylation, detosylation and oxidative decomposition, are discussed. Introduction of tosyl groups considerably lowers the decomposition temperature and enhances the char yield of cellulose acetate and cellulose benzoate. The data obtained from TG for the various stages of thermal degradation have been utilized to obtain various thermodynamic parameters using the method of Broido. The IR spectra of the residual char of cellulose esters indicates the formation of CC and CO groups in the final residual char. The mechanisms of the thermal degradation of these compounds are discussed.