Chemical modification of Norway spruce and Scots pine - A C-13 NMR CP-MAS study of the reactivity and reactions of polymeric wood components with acetic anhydride

Analysis by CP-MAS C-13 NMR of solid samples of wood, lignin, cellulose and holocellulose treated with acetic anhydride gas showed that in wood both acetylation and substitution of free sites of the aromatic ring occur readily in lignin both when alone and when in presence of carbohydrates such as in the wood matrix; that further rearrangements of the new substituents on the aromatic nuclei of lignin also occur inferring real or potential network cross-linking: that acetylation on the carbohydrates occurs to a considerably lesser extent than on lignin; that acetylation proper occurs on the carbohydrates at C6, and to a greater extent when in the wood then when alone due apparently to the presence of an additional acetylation site.