Solid state production of cellulose-chitosan blends and their modificationwith the diglycidyl ether of oligo(ethylene oxide)

Blends of the naturally occurring polysaccharides, cellulose and chitosan, obtained in the solid phase by the combined action of high pressure and she ar deformation using various equipment, were studied. It was shown by IR-sp ectroscopy that the system of hydrogen bonds formed between hydroxyl and am ino groups of the polysaccharides undergoes a qualitative change. This prov ides evidence that the blending of polysaccharides occurs at the molecular level. A mechanism of cellulose-chitosan blend formation in the presence of a diepoxide as a crosslinking agent was also studied. It was established t hat the crosslinking agent reacts predominantly at the amino groups of chit osan, with the formation of a three-dimensional network, cellulose macromol ecules being located within and partially bound with this network by the cr osslinks. It is shown that the formation of the aforementioned structures r esults in the insolubility of cellulose-chitosan compositions in acidic and alkaline aqueous media. (C) 2001 Elsevier Science Ltd. All rights reserved .