Synthesis And Application Of 2-Hydroxypropyltrimethyl Ammonium Chloride Chitosan

The developments of synthesis and application of chitosan derivatives were reviewed. 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was prepared. The microbiocidal activity of HACC and interaction between HACC and various kinds of surfactants have been studied. Chitosan/2-hydroxypropyltrimethyl ammonium chloride chitosan (CS/HACC) co-mixed microspheres were prepared, and their absorption effects were test. HACC was used to modify glass carbon electrode, and its electrochemical properity was studied.The following are the main contents and conclusions:1. HACC was prepared by the reaction of chitosan with 2,3-epoxypropyltrimethyl ammonium chloride. The effect of pH in reaction mixture on yield and solubility of the product was investigated, and reaction mechanism was discussed. The results showed that the yield of water soluble HACC was higher when the reaction was at pH 6.0 than at pH 4.0, 7.0 and 9.0, respectively. HPLC was used to characterize the change of molecular weight. The molecular weight of product is lower than the native chitosan.2. The interaction between HACC and various kinds of surfactants was studied by the means of compatibility, and surface tension. It was found that there was good compatibility between HACC at the concentration of 1×10^-3g/ml and hexadecyl trimethyl ammonium bromide (CTAB), Triton X-100 and Dodecyl betaine (C₁₂BE). The solution of HACC at the concentration of 1×10^3-g/ml and sodium dodecyl sulfonate (SDS) above the concentration of 1×10^3-mol/L could cause precipitation. HACC caused the surface tension curve to form a transition area and increased the critical micelle concentration (cmc) of CTAB and TritonX-100.3. Conventional agar plate method was utilized to evaluate the microbiocidal activity of HACC. The results show that HACC with different molecular weights (Mw 41.55×10⁴, 9.02×10⁴, 3.57×10⁴, 0.17×10⁴) showed biocidal activity on Staphylococcua aureus (S. aureus), Bacillus subtilis(B. subtilis) Staphylococcua epidermidis{S.epidermidis) and Candida albicans(C.albicans). HACC with high molecular weight had high biocidal activity on the gram-positive bacteria, and the biocidal effect of HACC decreased with decreasing molecular weight from Mw 9.02×10⁴ to Mw 0.17×10⁴. However, no remarkable biocidal activity of HACC was found on gram-negative bacteria Escherichia coli(E. coli) and Pseudomonas aeruginosa(P .aeruginosa) at the concentration up to 10 g /L. Existence of cationic surfactant, amphotericsurfactant, nonionic surfactant, Ca²⁺ and Mg²⁺ had no remarkable effect on microbiocidal activity of these HACC samples. 4. A series of chitosan/2-hydroxypropyltrimethyl ammonium chloride chitosan (CS/HACC) co-mixed microspheres were prepared by emulsificating-chemical crosslinking method. The absorption effect on sodium pentachlorophenate and acid chrome blue K was studied. The results showed that the absorption effect on sodium pentachlorophenate increased with the increasing ratio of HACC, while the physical structure of microspheres turned bad. CS/HACC co-mixed microsphere had absorption effect on acid chrome blue K.5. Glass carbon electrode was modified by HACC through covalent-bond reaction. The electrochemical behavior of nitrobenzene with low concentration on the modified electrode was studied and the reaction mechanism was discussed. The modified electrode show well stability and catalytic activity electrochemical reduction of nitrobenzene.