| 摘要 |
A condensation product of chitosan is formed by its reaction with a bisulfite addition compound HOCRR'SO3A wherein: each of R and R' independently represents a hydrogen atom, or R represents a hydrogen atom and R' represents an optionally substituted linear or branched saturated or unsaturated hydrocarbon group having up to 10 carbon atoms or an optionally substituted alicyclic, aromatic carbocyclic or heterocyclic ring, or R represents a CH3 group and R' represents an optionally substituted primary alkyl group, or R and R' together represent an optionally substituted alicyclic or heterocyclic ring, and A represents an alkali metal or ammonium ion. The condensation product/polymer is an anionic polyelectrolyte and forms stable anionic solutions in water at neutral pH. Such solutions may be mixed with other water soluble anionic polyelectrolyte, especially sodium alginate, to form very intimate admixtures or blends from which films, fibers, powders, sponges, gels and foams may be prepared. The chitosan may be regenerated from the condensation product in those films, fibers, powders, sponges, gels and foams by acid or alkali treatment during or subsequent to their production. The solubility of the condensation product also opens the way to a novel method for the extraction of chitosan from chitin/calcium carbonate mixtures. |
