Acetylation of wood components and fourier transform infra-red spectroscopy studies
In this study, the reactivity of wood components with acetic anhydride or vinyl acetate was studied. It was found that the reactivity of wood components was virgin wood flour > holocellulose >> a-cellulose. Acetylation of Turkish pine or cedar wood flour with acetic anhydride was significantly improved in the presence of potassium carbonate at 100°C. Maximum of about 20 and 18% weight percentage gain (WPG) values were obtained with Turkish pine (Pinus brutia) and cedar (Cedrus libani) wood flour after 3 h reaction at 100°C, respectively. The two modification methods and the effect of wood components on vinyl acetate (VA) or acetic anhydride (AA) modification, were characterised by infrared analysis in detail. As an apparent advantage of this new method, acetaldehyde was formed as by-product which is non-acidic was removed easily after the reaction due to low the boiling point of acetaldehyde [b.p. (760 mm Hg) = 21°C].
Key words: Acetic anhydride, vinyl acetate, holocellulose, α-cellulose, FTIR, chemical modification