Abstract: Thermal characterizations of four fractional celluloses and hemicelluloses isolated by alkaline hydrogen peroxide from defatting Mucuna sempervirens fiber were studied. Thermal gravimetric (TG) experiments determined the initial decomposition temperature (Tdi), maximum decomposition (Tdm), final decomposition (Tdf) and caput mortuum amount of four fractional celluloses and hemicelluloses. Differential scanning calorimetry (DSC) analysis demonstrated that thermal decomposition of four fractional celluloses and hemicelluloses includes the five phases of ice crystals melt, water endothermic evaporation, fusing, thermal pyrolysis and final hard coke thermolysis during the scanning range between -50℃ and 550℃. Moverover, the onset temperatures (TOS), peak temperatures (TPS), end temperatures (TES) and endothermic enthalpies of their fusing and thermal pyrolysis endothermic peak were also measured. The Kissinger equation was successfully applied to describe the thermal decomposition process of four fractional celluloses and hemicelluloses. The kinetic parameters of apparent activation (E) and reaction order (n) were obtained, respectively.

Key words: Mucuna sempervirensHemsl., cellulose, hemicellulose, pyrolysis kinetic