The Study Of The Preparation And Properties Of Antibacterial Regenerated Cellulose Fibers

Regenerated cellulose fiber which is naturally non-toxic and degradable,meeting the needs of sustainable development.Explore the preparation of cellulose materials with antibacterial functions,realize the functional utilization of regenerated cellulose,and promote the development and utilization of regenerated cellulose.In this paper,nano-silver,curcumin,catechin extract are used as antibacterial agents.Cellulose was modified by the in-situ generation and blending modification method before spinning,and three different regenerated cellulose antibacterial fibers are prepared by the dry spray wet method.Use different characterization methods to study the effect of antibacterial agents on the properties of regenerated fibers.The main research and conclusions are as follows:In the cellulose solution,polyethyleneimine as a stabilizer,and nano-silver particles are generated in situ by a one-pot method,and then the nano silver/regenerated cellulose composite fiber was prepared by the dry spray wet method.The influences of silver nitrate concentration,reaction time,and stabilizer on the formation of Ag NPs were investigated by UV-vis spectrophotometry.The particle size of nano silver is distributed in 7-13nm,evenly distributed in the regenerated composite fiber,it has little effect on the chemical structure,crystallinity and mechanical properties of the regenerated fiber.The antibacterial diameter of the regenerated composite fiber against Staphylococcus aureus is 1.1-2.9mm,the antibacterial rate is 82.5-98.12%,the antibacterial diameter of Escherichia coli is 6.5-8mm,and the antibacterial rate is 89.3-99%.Curcumin was used for antibacterial modification of cellulose by a physical blending method,and the curcumin/regenerated cellulose composite fiber was characterized.The research results show that the surface and cross section of the regenerated composite fiber are smooth.There is a new characteristic peak at 1513 cm^-1 in the FTIR,it prove that curcumin was successfully added to the regenerated composite fiber.The addition of curcumin with different concentration has little effect on the thermal stability and crystallinity of the regenerated fiber,and the mechanical properties are slightly reduced.The antibacterial rate of the regenerated composite fiber against Staphylococcus aureus is 80.7%-93.6%,and the antibacterial rate of Escherichia coli is 57%-76.3%.The cheap crude catechu was ultrasonically extracted with 75%ethanol to obtain the catechu extract.The catechin extract is blended with the cellulose solution to prepare the catechin/regenerated cellulose composite fiber.The research results show that the addition of appropriate amount of catechin extract can improve the mechanical strength and thermal stability of the regenerated fiber.When the addition amount of catechu extract is 5wt%,the mechanical properties of the regenerated composite fiber are the best,reaching 350Mpa.When the addition amount is15wt%,the surface of the regenerated composite fiber appears ravine streaks,the crystallinity decreases,and the mechanical properties decrease significantly.The antibacterial rate of the regenerated composite fiber against Staphylococcus aureus is 85.5%-99%,and the antibacterial rate of Escherichia coli is 43.2%-72.9%.In addition,this thesis also briefly describes the antibacterial mechanism of each antibacterial agent,and compares and analyzes the difference in antibacterial properties of three regenerated composite fibers.