羧甲基壳聚糖的合成

ABSTRACTChitosan (CTS),as an important macromolecule organic compound,is widely used inchemical industry,medical treatment,food manufacturing and other industries.Butbecause of its special properties,besides acid,it is insoluble in water-borne solvents,andCTS can hydrolyze in concentrated acid,so its practical use is not very extensive.Therefore,the structure modification of chitosan can greatly change its solubility.In this paper,chitosan was used as raw material to synthesize carboxymethyl chitosanwith good water solubility by chemical modification of chitosan with chloroacetic acidunder alkaline conditions.Secondly.the effects of synthesis conditions such as reactiontemperature,time and quality of chloroacetic acid on the degree of substitution ofcarboxymethyl chitosan were investigated.The structure and degree of substitution of theproduct were also determined by infrared spectroscopy.The results show that the degree ofcarboxymethyl substitution of the product increases from 1 h to 3 h,increases first and thendecreases from 40 to 60 and the degree of carboxymethyl substitution of the productincreases first and then decreases when the mass of chloroacetic acid increases from 2.0 gto 2.8 G.CONCLUSION:Carboxymethyl chitosan with high degree of substitution can beobtained with reaction time of 2 hours,reaction temperature of 50 C and mass ofchloroacetic acid of 2.4 G.Key words:chitosan;chloroacetic acid method;degree of substitution;carboxymethyl chitosan