ACETYL DISTRIBUTION IN ACETYLATED WHOLE WOOD AND REACTIVITY OF ISOLATED WOOD CELL-WALL COMPONENTS TO ACETIC-ANHYDRIDE

Lignin, holocellulose, cellulose, and hemicelluloses were isolated fro m pine wood and reacted with acetic anhydride. The order of reactivity was found to be lignin > hemicelluloses much greater than holocellulo se. Cellulose did not react. At a level of bonded acetyl where ah the hydroxyl groups were substituted on the lignin polymer, only about 20% of the total theoretical hydroxyl groups on the holocellulose were su bstituted. The data suggest that in the reaction of chloroacetic anhyd ride with whole wood, the initial rate-controlling step is the rate of diffusion of reactive chemical into the cell wall.