Preparation of Cu2+-Chitosan Quaternary Ammonium Salt-g-Poly(acrylicacid) with Efficient Antibacterial Activity

Acrylic acid(AAc) was grafted to chitosan quaternary ammonium salt(HACC) by ammonium persulfate as an initiator. HACC-g-PAAc-Cu2+ with efficient antibacterial activity was further prepared through complexation of Cu2+ with HACC-g-PAAc. The chemical structure of the grafted HACC was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance(H-1 NMR). The capacity of grafted HACC loading Cu2+ was determined by ultraviolet-visible spectroscopy(UV-Vis) and thermagravimetric analysis(TGA). Antimicrobial property of HACC-Cu2+ and HACC-g-PAAc-Cu2+ against staphylococcus aurous (S. Aurous) and E. coli bacillus were tested. Toxicity for oral intake of mice and coating irritation on rabbit skin of HACC-Cu2+ and HACC-g-PAAc-Cu2+ were also evaluated. The property of antibacterial and capacity of complexing Cu2+ can be improved by grafting of AAc. The molar ratio of Cu2+ / HACC increased from 3 : 7 be. fore grafting to 1 : 1 after grafting. The minimum inhibitory concentration(MIC) of S. Aurous and E. coli bacillus decreased from 60 mg/L to 9. 2 mg/L and 37 mg/L to 6. 3 mg/L. Moreover, HACC-Cu2+ and HACC-g-PAAc-Cu2+ have no toxic ingestion and skin irritation.