Chemical modification of wood. I use of trifluoroacetic anhydride in the esterification of wood by carboxylic acids

Treatment of beech sawdust with a series of mono‐ and dicarboxylic acids in benzene solution at 25–30° in the presence of molar proportions of trifluoroacetic anhydride resulted in esterification of the cell wall components. The esterification is shown to be due in part to acylation by the carboxylic acid and in part to trifluoroacetylation. The latter caused discoloration of the wood due to slow hydrolytic release of trifluoroacetic acid on storage at room temperature. Similar esterification of sapwood lengths of Ponderosa pine resulted in surface modification only and was accompanied by a significant decrease in impact strength property.