Thermal behaviour of some homogeneously esterified products of high α -cellulose pulps of fast growing plant species

Abstract

High α -cellulose pulps obtained from fast growing plant species Leucaena leucocephala and Hibiscus cannabinus were esterified with trimellitic anhydride (TMA), phthalic anhydride (PTA) and trimethyl acetic anhydride (TMAA), following a homogeneous reaction procedure. The degree of substitution achieved was found to vary, up to 2.56, depending on the reaction conditions. Thermal decomposition was studied by a differential thermogravimetry at three heating rates 5, 10 and 20°C min⁻¹ in static air. The kinetic parameters were evaluated using the generalized equation of Coats and Redfern. The thermal stabilities of the esters were found to vary in the order TMA > PTA > TMAA. The decomposition process was found to conform to first order weight loss kinetics, and the activation energies of the respective esters at 5°Cmin⁻¹ heating rate were 308.11, 194.98 and 213.00 kJ mol⁻¹ respectively.