Abstract:

Watersoluble hydroxybutyl chitosan(HBCS) was prepared by the reaction of chitosan(CS) with 1,2butane oxidation in an alkali solution. The structure of HBCS was characterized by FTIR and solid state ¹³C NMR, and the results prove that the hydroxybutyl has been successfully connected to chitosan molecular chain. The degree of hydroxybutyl substitution estimated by means of elemental ananlysis is 1.2. Besides, HBCS exhibited good watersolubility and could dissolve in aqueous solutions in a broader pH range. Incomparison with CS, HBCS shows a poorer thermostability. This is because the modified reaction destroys the crystalline region of chitosan. Antibacterial activities of CS and the modified derivative were explored by turbidity method. The results show that HBCS exhibits antibacterial activity against E.coli and S.aureus, and with the increase of concentration, the antibacterial effect enhances obviously. It was found that the antimicrobial activity of HBCS is weaker
 than that of CS under the same mass concentrations.

Key words: chitosan； hydroxybutyl chitosan； structure characterization； physiochemical property