Thermal decomposition kinetics of balsa wood: Kinetics and degradation mechanisms comparison between dry and moisturized materials

摘要

Thermogravimetric analyses under air atmosphere were performed up to 973 K on balsa wood to investigate the thermal degradation process of two types of samples aged differently: a dry balsa specimen and a hygroscopically aged material. The Kissinger method was used to determinate the kinetic parameters as the activation energy E_a, the pre-exponential factor k_0 and the order of reaction n. The three constituents of balsa (i.e. hemicellulose, cellulose and lignin) were well identified and the decomposition temperature region well characterized. The presence of a large quantity of water affects the thermal decomposition behavior of wood inducing notably a maximal degradation temperature higher by 314 K in relation to the dry material. The determined experimental kinetic parameters E_a, k_0 and n are in good agreement with those find in the literature for woods. The role of diffused water in the different thermal behavior between dry and aged balsa is explained from physical and chemical points of view.