Commercial flame retardants in four varieties of eucalyptus

ABSTRACT:

The objective of this work was to verify the flame retardancy capacity of two commercial products applied in four forest species (Eucalyptus saligna, Eucalyptus dunnii, Corymbia maculata and Eucalyptus grandis) evaluating their loss of mass throughout the combustion process and the behavior of the when subjected to high temperatures. In this, 9 samples of each species were used. For the physical characterization of the species (apparent mass (g/cm³) and porosity (%)), 15 samples of each were prepared, totalizing 96 randomly selected test pieces (2.5 x 2.5 x 2.5cm). All were stabilized at 12% humidity in a heated room. Then, with the aid of a brush, three layers of the products tested on the samples were applied, and these were applied at 24 hour intervals. The dilution of the products obeyed the recommendations of their manufacturers. For the combustion of the samples, a Bunsen nozzle was used, where the samples were subjected to the flame of oxidation until the loss of 80% of its mass over time. During the combustion process, every 30 seconds, the mass loss occurred in the sample in this time interval. Thus, it was possible to obtain curves that allowed to analyze and to characterize the thermal resistance of the wood based on the loss of mass of the different species studied here. Both products proved to be effective as regards the retarding ability of mass loss of samples when at high temperatures, but the product based on nitrogen and borates is more efficient compared to the product based on synthetic resin pigmented with flame retardant additives (flame retardant paint). Regarding the effectiveness of these on the woods, the results vary according to the species studied and this possibly due to the chemical composition of each variety.

Key words
Eucalyptus; combustion; loss of wood mass; flame retardancy