Chitosan is a kind of new low cost and environmental friendly natural polymer material

which has no toxicity

biocompatibility and biodegradability

so it has better application prospect in water treatment field. However

the chitosan has the disadvantages of acid solubility

low mechanical strength

limited number of functional groups

poor water treatment effect

etc.

chitosan generally needs to be modified. In this paper

the latest research progress of cross-linking and grafting in chitosan chemical modification is introduced. Crosslinking can improve the acid solubility of chitosan

the commonly used crosslinked agents include glutaraldehyde

epichlorohydrin

ethylene glycol diglycidyl ether

tripolyphosphate

etc. The graft methods can be used for the poor treatment of chitosan. The functional groups of grafting include amino group

carboxyl group

alkyl group

etc.

but the number of functional groups of grafted small monomers is limited

polymer grafting can be used to improve the performance of water treatment. Polymer grafting is a relatively new

low cost

modification method that can introduce a large number of functional groups and has a broad research perspective.