Cationization of kappa- and iota-carrageenan - Characterization and properties of amphoteric polysaccharides

BARAHONA, TAMARA; PRADO, HÉCTOR J.; BONELLI, PABLO R.; CUKIERMAN, ANA L.; FISSORE, ELIANA L.; GERSCHENSON, LIA N.; MATULEWICZ, MARÍA C.

CARBOHYDRATE POLYMERS

ELSEVIER SCI LTD

Año: 2015 vol. 126 p. 70 - 77

0144-8617

Commercial kappa- and iota carrageenans were cationized with 3-chloro-2-hydroxypropyltrimethylammonium chloride in aqueous sodium hydroxide solution. For kappa-carrageenan three derivatives with different degrees of substitution were obtained. Native and amphoteric kappa-carrageenans were characterized by NMR and infrared spectroscopy, scanning electron and atomic force microscopy; methanolysis products were studied by electrospray ionization mass spectrometry. Young moduli and the strain at break of films, differential scanning calorimetry, rheological and flocculation behavior were also evaluated; the native and the amphoteric derivatives showed different and interesting properties. Cationization of iota-carrageenan was more difficult, indicating as it was previously observed for agarose, that substitution starts preferentially on the 2-position of 3,6-anhydrogalactose residues; in iota-carrageenan this latter unit is sulfated.