Chemische synthese verzweigter polysaccharide, 10. Polymere mit amidartig gebundenen mono- und oligosaccharid-seitenketten
✍ Scribed by Emmerling, Winfried N. ;Pfannemüller, Beate
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1983
- Weight
- 883 KB
- Volume
- 184
- Category
- Article
- ISSN
- 0025-116X
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✦ Synopsis
Binding of mono-, di-, and ohgosaccharides by amide linkage to polymers carrying carboxylic or amino groups was studied with synthetic polymers (poly(acry1ic acid), poly(viny1amine)) and polysaccharide derivatives (e. g. chitosan). Suitable methods are described which allow a variation of the number and length of the attached saccharide branches. In the absence of salt, all products with a degree of substitution (DS) < 1 show polyelectrolyte behaviour.
Compared with the unsubstituted polyelectrolytes, for the branched polymers a substantial increase of the viscosity was observed within a certain range of branch density. In the case of glucose side chains, the maximum viscosity was found near DS = 0,l. In the case of maltose side chains, this maximum of the viscosity occurred at higher DS. A similar but smaller increase in the viscosity was observed in 0,l M NaCl solution. The results are explained by a shielding of the backbone charges from the counterions and by an additional chain stiffening effect resulting from hydrogen bonds, i.e., ring formation between the amide linkage and adjacent free carboxyhc or amino groups.