Process for washing a polysaccharide-based material which has been subjected to an oxidation

摘要

The present invention relates to a process for washing a polysaccharide-based material which has been subjected to oxidation by at least one oxidizing agent, the said process comprising a first stage of washing with a first densified fluid which is inert with regard to the said oxidizing agent, characterized in that the first stage is followed by a second stage of washing with a washing composition comprising at least one second inert densified fluid and at least one alcohol. The said process according to the invention can additionally comprise a third stage of washing with a third inert densified fluid in order to remove the said alcohol deposited on the said polysaccharide-based material during the said second washing stage. Preferably, the said inert densified fluids are supercritical carbon dioxide.

主权项

1. A process for washing a polysaccharide-based material which has been subjected to oxidation by at least one oxidizing agent, the process comprising;
a first washing stage in which the polysaccharide-based material is flushed with a first densified fluid which is inert with regard to the oxidizing agent; a second washing stage in which the polysaccharide-based material after the first washing stage is flushed with a washing composition comprising at least one second inert densified fluid and at least one alcohol, the second inert densified fluid is selected from the group consisting of carbon dioxide, xenon, argon, krypton, ethane, propane, hexafluoroethane, trifluoromethane, chlorotrifluoromethane, chlorodifluoromethane, dichlorodifluoromethane, and mixtures thereof, and a third washing stage in which the polysaccharide-based material after the second washing stage is flushed with a third inert densified fluid, wherein the polysaccharide-based material which has been subjected to oxidation is oxidized cellulose.