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Verfahren zur Herstellung von Cellulosesulfat mit verbesserten Eigenschaften

Preparation of regioselective substituted cellulose sulfate, useful in microencapsulating bio-material, comprises generating initial cellulose; adding sulfating- and acetylating agent; neutralizing; deacetylating, washing and drying
 
: Hauser, O.; Fischer, S.; Hettrich, K.; Wagenknecht, W.

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Frontpage ()

DE 102005011367 A: 20050311
DE 2005-102005011367 A: 20050311
WO 2005-EP2871 A: 20050317
WO 2006-EP60626 A: 20060310
DE 102005011367 A1: 20060914
Deutsch
Patent, Elektronische Publikation
Fraunhofer IAP ()

Abstract
Die Erfindung betrifft ein Verfahren zur Herstellung von Cellulosesulfat, das auch bei niederem DS vollstaendig wasserloeslich ist und sich auf Grund der biologischen Vertraeglichkeit, der hohen Loesungsviskositaet in waessriger Loesung und der sehr guten Reaktionsfaehigkeit mit Polykationen als Hilfsstoff fuer biologische und medizinische Anwendungen eingesetzt werden kann und insbesondere fuer die Immobilisierung von biologischen Objekten, wie z. B. Gewebe, Zellen, Mikroorganismen, Enzyme oder Viren, in Mikrokapseln geeignet ist.

 

DE 102005011367 A1 UPAB: 20061010 NOVELTY - Preparation of regioselective substituted cellulose sulfate comprises: generating initial cellulose in polar aprotic solvent; adding sulfating- and acetylating reagent for simultaneous esterification of mixture and distribution of acetate- and sulfate group along the polymer chain; directly and completely neutralizing the mixture with sodium hydroxide; and deacetylating, washing and drying the sodium salts, which has a solution viscosity of greater than 10 mpas at a concentration of 1% in water. DETAILED DESCRIPTION - Preparation of regioselective substituted cellulose sulfate comprises: generating initial cellulose in polar aprotic solvent; adding sulfating- and acetylating reagent for simultaneous esterification of mixture and distribution of acetate- and sulfate group along the polymer chain; directly and completely neutralizing the mixture with sodium hydroxide (where the sulfate is transferred with/without splitting the acetyl group into a sodium cellulose sulfate (NaCS) and avoiding the decomposition of cellulose chain); and deacetylating, washing and drying the sodium salts, which has a solution viscosity of greater than 10 mpas at a concentration of 1% in water. INDEPENDENT CLAIMS are included for: (1) a sodium cellulose sulfate (A) exhibiting a solution viscosity of 10-500 (preferably 20-50) mPas at a concentration of 1% in water; (2) the preparation of microcapsule comprising: preparing aqueous sodium salts solution (0.5-10%); preparing the NaCS encapsulated suspension by supplementing the encapsulated materials to the aqueous NaCS solution and optionally the supplementing the further carrier materials, additives, solvents or preservatives, salts, glycerin or dimethyl sulfoxide; dropping; and complexing the capsule in the polymerization bed; and (3) a microcapsule from NaCS. USE - NaCS is useful in the microencapsulation of biological material; and in the preparation of microcapsule. The microcapsule is useful for implanting and/or injecting (all claimed). ADVANTAGE - The process is an improved process.

: http://publica.fraunhofer.de/dokumente/N-51794.html