Tartaric acid catalyzed furfurylation of beech wood

Abstract

European beech (Fagus sylvatica L.) is a major tree species of European forest which is underexploited because of its low dimensional stability and durability. Similarly to what has been developed with radiata pine, furfurylation might be the answer to optimize the utilization of local beech wood. Beech wood furfurylation process was studied using five different catalysts: maleic anhydride, maleic acid, citric acid, itaconic acid, and tartaric acid. Optimization of the furfurylation process was investigated for different catalyst and furfuryl alcohol (FA) contents, and different duration of polymerization. The following properties were studied: weight percent gain (WPG), leachability, anti-swelling efficiency (ASE), wettability, modulus of elasticity, modulus of rupture, Brinell hardness, and decay durability. Tartaric acid, never investigated up to now, was retained as catalyst to perform furfurylation due to its efficacy compared to other catalysts and its novelty. Wood modification with FA and tartaric acid as catalyst led to samples with high WPG even after leaching, improved ASE, and lower wettability with water. Increasing the polymerization duration increased the fixation of FA in treated wood. Most of all, treatment gave a significant improvement in mechanical properties and resistance to wood decaying fungi.