A Study of the Best Conditions for the Acetylation of P. taeda from Uruguay

Chemical modification is an environmentally friendly option for wood preservation. It can improve the performance and dimensional stability of wood, increase its resistance to deterioration and ensure safe disposal once out of service. Wood acetylation is the esterification of accessible hydroxyl groups in the cell wall with acetic anhydride, which reduces the hygroscopicity of wood. Acetic acid is obtained as a byproduct of the reaction. The aim of this work is to determine the best reaction conditions for the acetylation of Pinus taeda wood with acetic anhydride. The experimental design used was a 22 factorial design with three repetitions in the midpoints. Reaction temperature and reaction time were taken as independent variables, each at two levels. The weight gain percentage of wood (WPG) and its chemical changes were used as response variables. The durability of the wood acetylated under the best treatment conditions as determined before was tested against decay fungi (Gloeophyllum separium and Trametes versicolor). The results show that temperature was the most impactful variable on the WPG results. Higher WPGs were obtained at temperatures above 100 °C. The acetylated wood was highly resistant to fungal attack, with very low mass losses.