Study Of Cotton And Propylene Non-woven Fabrics Finishing With Chitosan-Ag～+ Compound Antibacterial Agent

With the improvement of people's living standard, there is an increasing demand for ecology functional textiles. The use of those kinds of textiles has developed into a major trend in the 21^st century and the exploration of antibacterial textiles is gaining more and more attention. Among various antibacterial agents, chitosan and Ag⁺ are widely used. They are highly effective and safe. However, the combination use of these two agents has been litter reported. This thesis mainly focus on the preparation of chitosan-Ag⁺ compound antibacterial agent and the antibacterial finishing of non-woven fabrics made of cotton and polypropylene fibers.First of all, a certain amount of chitosan was dissolved into 0.5 mol/L acetic acid solution and the pH value was adjusted to about 5.0. Then a certain amount of 400 mg/L silver nitrate solution was added to the previously prepared solution through a pipette. Finally, certain assistant agent was also added and the pH value was kept at 5.0. Then the mixed solution was mixed fully with a high-speed stirrer. After being exposed to air for about four hours, the stable chitosan-Ag⁺ compound antibacterial agent could be obtained.In this paper, the antibacterial finishing of non-woven fabrics made of cotton and polypropylene fibers was carried out by using the chitosan-Ag⁺ compound antibacterial agent following the finishing process of pad-drying. Influences of various process parameters on antibacterial effect, washability as well as basic performances were analyzed through experiments. On the basis of ensuring good antibacterial effect and maintaining the basic performances of fabric, the finishing process parameters was set as following from the aspect of reducing cost.For non-woven fabrics made of cotton, the concentration of antibacterial agent was 4%(o.w.f) and the bath rate was 1:20 and the pH value was about 5.0. The fabrics was cured at 150°C for 90 seconds. Whereas, for non-woven fabrics made of polypropylene fibers, the fabrics was dried at 100°C for 120 seconds.The antibacterial effect of the fabrics was measured according to the AATCC-90 and AATCC-100 as well as color reaction of Ag⁺ and sulfured sodium.Besides, for the stable complexing effect of chitosan on Ag⁺, the inhibition of chitosan on discoloration of the Ag⁺ was also investigated in this paper. By comparison with the antibacterial fabrics treated by inorganic nano-SiO₂-Ag⁺ antibacterial agent, it was found that the chitosan-Ag⁺ compound antibacterial agent had a better restraining effect on the discoloration of Ag⁺.To sum up, the compound antibacterial agent has the merits of both dissolve-out and non-dissolve-out antibacterial agents. It is a kind of safe antibacterial agent which conforms to the developing tendency of fabric antibacterial agents. Environment-friendly chitosan-Ag⁺ compound antibacterial agent was prepared in this paper, which can be employed in antibacterial finishing for fabrics made of both hydrophilic and hydrophobic fibers. It can be widely used to finish the filtration fabrics, socks, underwear as well as some common fabrics used in such public places as hospitals, trains, hotels, etc. In a word, the compound chitosan-Ag⁺ antibacterial agent comply with the developing tendency of antibacterial textiles, thus it can be widely applied in many fields and has a very promising prospect.