Potential catalysts for the acetylation of wood

The potential of several tertiary amine catalysts (pyridine, 4-dimethyl-amino pyridine, N-methyl pyrrolidine and N-methyl pyrrolidinone) for the acetylation of Corsican pine sapwood, using acetic anhydride, has been investigated. Rates of reaction were compared with non-catalysed acetylation using acetic anhydride. The hypernucleophile 4-dimethylamino pyridine was found to be the most effective catalyst of those studied. At a concentration of only 1 % of the catalyst in acetic anhydride, a weight percent gain of 20 % was realised, compared with 7 % for the uncatalysed reaction, after 30 minutes system at 100 degrees C. The influence of substrate swelling upon the rate of reaction with wood is discussed.