Study on preparing technique of chitosan with narrow molecular weight distribution

Preparing technique of chitosan with narrow molecular weight distribution through ultrasonic processed was investigated.According to the rotary unitized design principles,the influence of temperature and the concentration of chitosan and acetic acid on the polydispersity of chitosan after ultrasonic process were studied and the mathematical model was established based on the basis of single factor experiments.The preparation conditions of chitosan with narrow polydispersity were obtained by variance analysis and the optimization of mathematical model.Results showed that the optimum conditions of ultrasonic process were that the temperature of 24℃,the concentration of acetic acid of 0.27mol/L and the concentration of chitosan of 1% according to the actual situation.The polydispersity of chitosan decreased from 11.51 to 4.25 after ultrasonic processed.