Estabilidade térmica de painéis aglomerados de bagaço de cana-de-açúcar e madeira de Pinus spp.

Abstract

The objective of this study was to evaluate the thermal stability of particleboards produced with different percentages of sugar cane bagasse, in combination with Pinus spp. wood, and different levels of ureaformaldehyde adhesive, in order to better understand the thermal degradation of these boards at intense heat situations. Nine treatments were evaluated, comprised of particleboards produced with different amounts of sugar cane bagasse, in replacement of Pinus wood (25, 50 and 75%), and in combination with three levels of urea-formaldehyde adhesive (6, 9 and 12%). Samples of approximately 5 mg were placed in alumina capsules and analyses were performed in a nitrogen atmosphere with a flow rate of 50 milliliters per minute. The rate employed was 10°C per minute until the final temperature of 600°C. The thermogravimetric curves were divided into two stages, according to the maximum mass variations obtained. Derivative thermo-gravimetry (DrTGA), which is the first derivative of the TGA curve, was also performed. It was observed that, regardless of the amount of adhesive used, the addition of sugar cane bagasse and, consequently, the decrease in Pinus spp. wood, resulted in the decrease in the thermal stability of particleboards. Regarding the effect of the increase in the content of adhesive on the manufacture of the particleboards, it was observed that there is a decreasing trend in the onset temperature and in the peak, and an increase in mass loss for the main degradation stage, especially when the particleboards produced with 6% and 12% urea-formaldehyde adhesive are compared.