The effect of the structure of a cross-linking reagent of the alkylating type on the properties of chitosan granules

The reactivity of chitosan in the form of granules towards a series of cross-linking reagents of alkylating type is compared. The following cross-linking reagents were considered: alkyl dihalides (1,2-dichloroethane, 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dichlorobutane, 1,5-dibromopentane), 2,2′-dichlorodiethylamine, 2,2′-dichlorodiethyl ether, 2,2-diethoxy-1-bromoethane, epichlorohydrin, diglycidyl ethers of ethylene glycol, and butane-1,4-diol. The composition and structural features of the obtained materials were characterized by elemental analysis and FTIR spectroscopy. On the basis of a number of characteristics of the granules such as degree of crosslinking, degree of swelling, static exchange capacity, sorption capacity towards CuII ions, it is shown that among the studied dihaloalkanes, chitosan reacts more efficiently with dibromo derivatives, and 1,3-dibromopropane is found to be the best cross-linking reagent. On the basis of the data on degree of swelling of the cross-linked granules, the cross-link density and the degree of crosslinking were calculated for different cross-linking reagents.