Preparation And Properties Of New ¦Â-cyclodextrin Chemically Modified Chitosan

A novel chitosan derivative beatingβ-cyclodextrin was synthesisized in this paper. The synthesis was divided into two steps: The first step was the preparation of carboxymethyl-β-cyclodextrin, then it was acyl chlorided. The second step was thatβ-cyclodextrin was grafted onto the chitosan skeleton by the action of acidamide. Different preparation conditions such as: weight ratio, time, temperature, etc, were investigated. And the optimal condition was gotten when the weight ratio of acyl chlorided carboxymethyl-β-cyclodextrin to chitosan was 4:1, reaction time was 16h and temperature was 90℃. This kind of chitosan derivative bearingβ-cyclodextrin had the chacracteristic of good acid resistance and base consistence,and it was determined by Infared Spectrum, Differential Thermal Analysis and X-ray Diffraction.The adsorptions of phenol,p-nonylphenol and resorcinol with this kind of chitosan derivative bearingβ-cyclodextrin under different conditions were investigated. The effects of temperature, pH, adsorption time and initial concentration on the adsorbing capability of this kind of chitosan bearingβ-cyclodextrin were studied. The results showed that its adsorption contents of adsorbing phenol, p-nonylphenol and resorcinol when temperature was 30℃, pH was 6.74,adsorbent weight was 0.02g ,adsorption time was 6h and initial concentration 30mg/L were 24.0mg/g,13.5mg/g,38.2mg/g, respectively. And its adsorptions of phenol, p-nonylphenol and resorcinol were optimal under the condition of temperature 30℃, pH =2.65, adsorption time 6h and initial concentration of phenols was 120 mg/L.At the same time, the capabilities of this kind of chitosan derivative bearingβ-cyclodextrin of absorbing Guanosine 5'-Monophosphate (GMP), Cytidine 5'- Monophosphate(CMP) and Uridine 5'-Mono phosphate(UMP),which were the main structural units of RNA,were studied as well.It was showed that its adsorption contents of adsorbing GMP, CMP, UMP when temperature was 25℃, pH was 7.10,adsorbent weight was 0.05g ,adsorption time was 6h and initial concentration of GMP, CMP, UMP was 150mg/L were 42.2mg/g,13.gmg/g,14.1mg/g, respectively, superior to the unmodified chitosan.And the optimal adsorbing condition was: temperature 25℃,pH=2.65, adsorption time 6h.