Preparation And Characterization Of Aromatic Acid/Chitosan Nanoparticles

In this paper,we introduced detailly the research progress in the water soluble low molecular chitosan preparation,separation,purification and application at home and abroad in recent years.This paper discusses the influence of reaction medium on degradation of chitosan in different reaction system.This paper discusses the optimum technological conditions of H2O2 oxidation degradation of chitosan in the homogeneous system and the degradation products were analyzed.This paper preliminary discusses the influence of heteropoly acid catalyst for hydrogen peroxide degradation of of high molecular weight chitosanin heterogeneous system.In this experiment,we investigated the relative molecular mass of the water soluble product oligochitosan,production rate,color,and material/product degree of chitosan,determination of molecular weight,structure and characterization.Our raw material is determined by acid-base titration degree of chitosan and product.By viscosity method for determining the relative molecular mass of chitosan raw materials;through the end group analysis method for' determination of relative molecular mass of the chitosan product;through infrared chromatographic analysis of the raw material of chitosan and product structures have been characterized.Results show that in homogeneous system,the optimal process conditions ofH2O2 oxidation degradation of chitosan is:t=6h;R=2;T=60?.The producing oligochitosan rate was 66.9%under this experimental condition,and the color of product is white or light yellow.In heterogeneous system,the yield of oligochitosan with phosphotungstic acid as catalyst reached 74.8%,molecular weight is 612.4,degree of deacetylation is 60.37%,shows that phosphotungstic acid is a kind of good catalyst for the degradation of chitosan,has broad application prospects.All in all,this paper discussed the H2O2 oxidation degradation of chitosan in the different reaction system,discovered that the phosphotungstic acid catalyst is a kind of ideal degrading chitosan.And this provides the theoretical basis and experimental evidence for the further development and application of water soluble low molecular chitosan.