Study On Antiseptic Paper And Wet Tisse Using Chitosan And Its Derivates As Antimicrobial Agents

Chitosan is a renewable natural product present in waste crab and shrimp shells. Till now it is the only basic polysaccharide found in nature. Its amount is only second to cellulose and its structure very similar to the latter. Our country is abundant in marine resources. Therefore it is very significant to produce chitosan from the shells wastes.Chitosan has wide antimicrobial properties. It and its derivates are widely used in textile, medicine, food and other fields, but applications in papermaking industry are much less. On the other hand, the application of chitosan is limited because it is only dissoluble in acidic solutions but not in water. Therefore it is important to modify chitosan.Accordingly, in this paper, water soluble carboxymethyl chitosan (CMCTS) was prepared and used to make antiseptic and wet tissue paper, with the purpose of enlarging their applications in paper industry.The first part of this paper studied the preparation of CMCTS. The effects of the dosage of etherifying agent, the dosage of alkali, the concentration of alkali, reaction time and reaction temperature on reaction ratio, degree of substitution (DS), molecular weight and solubility were thoroughly discussed. CMCTSs with degrees of substitution around 0.7～1.2 were made in this experiment. They were white to yellow, and dissolvable in water.The second part mainly studied the preparation of antiseptic paper. Two factors, the degree of substitution and dosage of CMCTS, were analyzed. The result showed that the antiseptic paper had good antimicrobial ability when the DS of CMCTS was about 1.02 and the dosage about 0.15%. In addition, CMCTS improved paper strengths to significant extents.Finally, the preparation of wet tissue paper was studied using .impregnation method. CMCTS had good moisture absorption and retention properties, on which CMCTS with DS 1.02 equaled to glycerol. The antiseptic effect of the wet tissue paper increased gradually with the increase of CMCTS concentration. When the DS of CMCTS was about 1.02, the concentration 0.05%, pH 6.3 and temperature 30℃, the antiseptic ratio approached 100%.