Comparative degradation kinetic studies of three biopolymers: Chitin, chitosan and cellulose

Cellulose, chitin and chitosan are the most abundant biopolymer on earth and constitute an important class of biodegradable materials. The decomposition of three major biopolymers viz. chitin, chitosan and cellulose are studied using simultaneous thermal analysis i.e. thermogravimetry/differential thermal analyzer (TG/DTA). Thermal analysis is performed from ambient temperature to 700 °C in a flowing nitrogen medium at four different linear heating rates i.e. 2.5, 5, 10 and 20 °C min. Thermal stability order of the three biopolymers based on TG followed the order: cellulose > chitin > chitosan. Non-isothermal multiple heating rate model free methods Ozawa-Flynn-Wall (O-F-W), Kissinger, Friedman and modified CoatsRedfern methods are used to calculate degradation activation energy of the biopolymers. The reaction mechanism based on activation energy calculation at different conversions has been proposed.