Chemical, Mechanical, Thermal, and Colorimetric Features of the Thermally Treated Eucalyptus grandis Wood Planted in Brazil

Abstract

This article aimed at thermally treating and charactering the Eucalyptus grandis wood under three different temperatures. For this, pristine eucalypt samples were treated by heating in a laboratory oven at 160 °C, 200 °C and 240 °C, always for 2 h. Treatment parameters (based on weight percentage loss and specific gravity), as well as mechanical (by hardness tests), chemical (by infrared spectroscopy), thermal (by thermogravimetry), and colorimetric (by CIELab method) features were evaluated. Compared to the pristine ones, the treated woods have there was a drop in apparent density at 12 % and consecutively greater thermal stability which is probably related to a previous partial degradation of some major amorphous components (namely cellulose, hemicellulose and lignin), as suggested by the treatment parameters and infrared spectra. Besides of that, the higher the temperature treatment, the higher the loss in surface hardness and the higher the colour darkening.