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

Abstract

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 Cu^II 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.