Características tecnológicas das madeiras de Corymbia citriodora e Eucalyptus grandis submetidas ao processo de encharcamento.

Abstract

This study aims to evaluate the influence of prolonged soaking on chemical, physical, mechanical and biological properties of Eucalyptus grandis Hill ex Maiden and Corymbia citriodora Hill & Johnson species of reforestation wood. Three trees of each species were obtained in homogeneous stands 50 years of age, from Centro Agropecuário da Palma, belonging to the Federal University of Pelotas. Obtaining samples occurred by dividing the trees into three parts, each 1000 mm height, which were named top, intermediate and base. Each part was subdivided into four samples with 250 mm height and denominated small logs. Of these, one was used as control sample and placed in a climatic room of 20°C and relative humidity of 65% to stabilize the wood at 12% of moisture content. The other small logs were immersed in water and taken out at different times: 4, 8 and 12 months. After each harvest, the others small logs were sent to the same climate conditions. The wood was characterized with static bending mechanical test, determination of specific gravity (EG) at 12%, contact angle and measurements of extractives, lignin, solubility in water and sodium hydroxide, sugars and qualitative analysis of the extractives were performed by pyrolyzer coupled to gas chromatography and mass spectrometry (Py-GC/ME) and spectroscopy attenuated total reflectance infrared (ATR -IR), as well as accelerated test with decay fungi. Results show that the wood mechanical resistance of the two species not decreased, if the treatment is for at least 12 months, and tested treatment, although cause little degradation of hemicellulose, densified wood, homogenized EG and increases biological resistance for the species Corymbia citriodora and Eucalyptus grandis.