The commonly used wood preservation treatments are nowadays facing huge environmental issues, as well as increasing public concern. As regards those concerns, legislation tends to regulate the use of biocidal preservation chemicals. Thus, it does appear crucial to provide alternatives to the use of biocides to allow different outdoor uses of wood such as for, posts, decking, and cladding or even for railway sleepers. Heat treatment of wood have been developed to improve its resistance against biodegradation and swelling effect, but the performance of heat treated wood remains limited toward certain wood destroying organisms (soft rots, termites). Moreover, mechanical properties of the thermally modified wood are widely decreased. Our study aims to provide new treatments for wood protection against biodegradation, by impregnation of aqueous solutions of various poly- carboxylic acids or anhydrides (citric acid, succinic anhydride, tartaric acid) and glycerol, followed by in situ heat polymerization. The chemicals mentioned are all bio-based, and allowed for food use (except succinic anhydride) The resistance of the polyesters formed in small Beech (Fagus sylvatica) has been established against leaching, according to the former ENV 1250-2 standard, for 31 hours. The resistance to fungal attack by Coriolus versicolor has been evaluated with a 6 weeks screening tests on the same samples. It has notably been showed the dependence of leaching rate on the heating temperature used for the process. Almost no leaching occurred by heating the samples at 140°C, or at higher temperature. Very low mass losses were obtained through decay resistance tests, showing the performance of the treatments regarding fungal resistance, especially at high curing temperatures. The characterization of the mechanical properties of modified woods shows promising results, by maintaining the resistance of wood in flexion. An Anti-swelling Efficiency and hydrophobicity are also provided by the modification performed.

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