Synthesis and characteristics of chitin and chitosan with the (2-hydroxy-3-trimethylammonium)propyl functionality, and evaluation of their antioxidant activity in vitro

► Quaternary amino groups were introduced into chitin and chitosan oligomers. ► Structures were determined by FTIR, the molecule weight were measured by GPC. ► Their antioxidant activities in vitro were further studied. ► Antioxidant activities of quaternized chitin/chitosan were better than chitosan.