Different methods of chitosan grafting with quercetin and determining the antioxidant activity of synthesized copolymers

Abstract

IntroductionChitosan has become one of the most interesting polymers in different fields due to a rare combination of biological, mechanical and physical activities. It is one of the main products of chitin, which is commercially obtained by chitin deacetylation produced by crustaceans. Reducing the molecular weight and thus decreasing the crystallinity, it is improved its solubility in diluted acids at pH = 5 where the free amine groups are protonated. In the synthesis of chitosan derivatives, three methods have been developed to produce chitosan compounds functionalized with polyphenols: ester-mediated modification; enzyme-mediated strategy; grafting induced by free radicals. The main purpose of experimental studies is the synthesis of chitosan derivatives by grafting it with certain compounds that exhibit antioxidant properties and represent part of the flavonoid class and studying, comparing the antioxidant properties of the obtained copolymers.