Rhodia Acetow Gmbh

Rhone-Poulenc Rhodia Aktiengesellschaft

Rhodia Acetow Aktiengesellschaft

Hans Steinmeier

Ties Karstens

Armin Stein

Karl Bredereck

Harro Lentz

The invention concerns reactive cellulose, i.e. cellulose having in particular a very low degree of crystallinity obtainable with a high degree of purity. Said novel reactive cellulose is particularly used as raw material for making cellulose ethers. The invention is characterized in that the reactive cellulose is substituted by organic groups according to a degree of substitution, DS, of less than 0.2, preferably between 0.04 and 0.2.

Reactive cellulose and method for making same

Process for activating polysaccharides, polysaccharides produced by this

The process for the treatment of cellulose for activation for subsequent chemical reactions by bringing the cellulose in contact with liquid ammonia at a pressure higher than atmospheric pressure in a pressure vessel and subsequent expansion by rapid reduction of the pressure to atmospheric pressure, is carried out by using a cellulose pulp of an alpha-cellulose content of at least 92 mass %, letting the ammonia act on the pulp at room temperature or at a temperature higher than room temperature, after the expansion, removing the ammonia then still remaining in the pressure vessel except for a minimum content at which the state of activation reached by the action of the ammonia is still maintained and finally replacing the residual ammonia still needed to maintain the state of activation by another swelling or inclusion agent. The process is suitable, also on a large industrial scale, especially for the activation of pulp subsequently to be acetylated and makes possible to achieve a homogenous and high-grade activation. Further, no costly cooling apparatus is needed.

Process for the treatment of cellulose

Growing community of inventors

Teningen, Germany

Hans Steinmeier