2,3-Dicarboxyamylose (DCA) and 2,3-dicarboxycellulose (DCC) have been obtained by splitting with periodate of all the C(2)-C(3) bonds of amylose and cellulose, and further oxidation (with chlorite) of the corresponding polydialdehydes. Small, but reproducible, differences of 13C chemical shifts in dicate that DCA and DCC retained the different configuration at C-1 of the original polysaccharides, therefore being stereoisomers. The potentiometric and conductimetric titration curves of DCA and DCC and the pH-dependence of their 1H n.m.r. spectra are those of typical polydicarboxylates. Interaction of DCA and DCC (Na salts) with divalent cations is clearly indicated by inflexions in conductimetric titration curves with Ca2+, Mg2+, Cu2+ and Fe2+, and by variation in specific optical rotation.
Dicarboxyamylose and dicarboxycellulose, stereoregular polyelectrolytes: physicochemical characterization and interaction with divalent cations
MEILLE, STEFANO VALDO;
1984-01-01
Abstract
2,3-Dicarboxyamylose (DCA) and 2,3-dicarboxycellulose (DCC) have been obtained by splitting with periodate of all the C(2)-C(3) bonds of amylose and cellulose, and further oxidation (with chlorite) of the corresponding polydialdehydes. Small, but reproducible, differences of 13C chemical shifts in dicate that DCA and DCC retained the different configuration at C-1 of the original polysaccharides, therefore being stereoisomers. The potentiometric and conductimetric titration curves of DCA and DCC and the pH-dependence of their 1H n.m.r. spectra are those of typical polydicarboxylates. Interaction of DCA and DCC (Na salts) with divalent cations is clearly indicated by inflexions in conductimetric titration curves with Ca2+, Mg2+, Cu2+ and Fe2+, and by variation in specific optical rotation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
