| 摘要 |
A method of producing cellulose carbamate is described in which: (a) cellulose is brought into contact with liquid ammonia at an initial pressure exceeding atmospheric pressure and a temperature of at least about 25 DEG C, in the presence of urea, the quantity of liquid ammonia sufficing at least to wet the surface of the cellulose; (b)the volume available to the cellulose-urea-liquid ammonia system is enlarged explosively, lowering the pressure by at least 5 bar, and an activated mixture of cellulose and urea is obtained; (c) the activated mixture of cellulose and urea is taken up in an inert organic carrier for the reaction, and heated to a temperature between about 110 DEG C and 150 DEG C to make cellulose carbamate, and (d) the organic reaction carrier and any urea not reacted are removed from the cellulose carbamate obtained. The method saves energy and supplies a very homogenous cellulose carbamate. |
