EFFECTIVENESS OF A OIL RESIDUE FROM PETROLEUM ON DIMENSIONAL STABILITY OF Pinus sp. (Pinus) AND Mimosa scabrella Bentham (Bracatinga) WOOD

Abstract

In search for alternative uses of a petroliferous oily residue known as “LCO” (Liquid Cycle Oil), its capacity to improve the dimensional stability of the wood was evaluated using Pinus sp. (pinus) and Mimosa scabrella Bentham (bracatinga). The LCO was tested in its original composition and also diluted in different proportions into a commercial kerosene. The dimensional stability in the three anatomic axis, volumetric changes, shrinkage and anisotropy coefficients, basic density and 12% relative humidity density changes were evaluated, in different stages during the investigation process. The results show no significant differences in maximum swelling and shrinkage between treated and untreated wood blocks at 5% probability level for both species. However, a reduction in the shrinkage coefficient was observed with the increase of LCO concentration, for both species. In general, pinus showed lowest values in all parameter evaluated. The shrinkage and anisotropy coefficient were higher for bracatinga than pinus, nevertheless, no significant differences were observed between treated and untreated wood blocks. These results indicated that changes between tangential and radial faces were minimal, possible due to a poor penetration of LCO into the cell walls. This result, as a consequence, could be associated with a weak performance of the tested chemical, which could not improve the dimensional stability of wood for both species. The increasing LCO concentrations increased the density of both species at 12% relative humidity. This result could be associated to the presence of part of the chemical remaining in the walls of the cellular lumen and the resiniferous channels. Besides, the external aspect of the treated wood was also other restrictive factor to the use of LCO.