Eficiência do óleo queimado na preservação de madeiras amazônicas submetidas ao ataque de cupins

Abstract

This study aimed to evaluate the efficiency of used engine oil on Amazonian woods exposed to xylophages termites. For this purpose samples of Trattinnickia rhoifolia (amescla), Erisma uncinatum (cedrinho) and Copaifera langsdorffii (copaíba), with dimensions of 2x2x10 cm, were submitted to preservative treatments by short-term soak (5 min) and long-term soak (24 h) in oily product with different viscosities, SAE 10W and SAE 15W. In attempt to better characterize wood structure and composition some of the wood samples were submitted to both chemical and physical analysis. Amescla wood obtanied the lowest values to chemical parameters. Cedrinho wood had the highest basic density, and Copaiba wood the lowest porosity value. From each sample, the retention rate of the used oil engine was determined. To evaluate the efficacy of preservative treatment, treated and non-treated samples were exposed to xylophagous termite (Nasutitermes sp.) under laboratory conditions. The exposure took 45 days straight, and at the end of this period weight loss of the wood samples were determined. The soak time and viscosity in used oil engine did not statically influence in the retention rate. Copaíba wood had the highest retention rate, differing from amescla and cedrinho wood. None of the samples treated with used oil engine was attacked by xylophages termite, which shows the efficiency of used engine oil in the preservative treatment. Among non-treated wood, copaiba and cedrinho wood had the highest and the lowest mass loss, respectively.