Silylation of cellulose with hexamethyldisilazane in liquid ammonia

Silylation of cellulose with hexamethyldisilazane (HMDS) in liquid ammonia at elevated temperature in an autoclave is reported. The influence of temperature, time, concentration of reagents and type of cellulose used for the silylation has been studied. The maximum degree of silylation achievable depends on the starting material. The new method gives higher degrees of silylation than other methods reported in the literature. As indicated by SEC the silylation of cellulose with HMDS/NH3 proceeds without degradation of the polymer chain. Silylation seems to change the mechanism of thermal degradation in thermogravimetric analysis with respect to that of cellulose.