Enhancing pine wood properties by two-step impregnation-heat treatment

ABSTRACT This study aimed to evaluate the efficiency of the combined treatment of rosin impregnation followed by heat treatment in Pinus sp wood. Fifteen cubic samples of 15mm edge were randomly selected. The first step consisted of the impregnation of thermoplastic resin based on rosin and the second step was the heat treatment of wood at 180°C for 30 minutes. The impregnations were performed by two different methods: vacuum-immersion (VT) and hyperbaric pressure (HBT). The vacuum period was 15min and total impregnation time was three hours. The pressure in the HBT treatment was 6000bar for 15min. The treatments were analyzed through the solution retention and mass loss. The evaluation of the physical characteristics was done through the analysis of water absorption rates, radial, tangential, volumetric swellings, wettability and thermogravimetric analysis. The decay resistance was evaluated by accelerated decay tests. The results showed the efficiencyof the treatments, especially the HBT treatment. The contact angle was constant over the timefor the treated wood samples, whereas, the untreated wood sampled presented hydrophilic behavior. The decay resistance of treated wood with VT and HBT treatments increased in relation to the untreated Pinus sp. wood. The combined treatment is a potential alternative to improve the physical properties of Pinus sp. wood.