Research On Antibacterial Function Finishing Of Cotton Fabric Based On Schiff Base-Halamine Compounds

Cotton fabric is widely used in daily life because of its comfortable wearing,good air permeability and excellent mechanical properties.But its good absorption of bacteria will cause disease transmission and harm human body.Therefore,it is very necessary to carry out antibacterial finishing to cotton fabrics.At present,among the antibacterial finishing agents,halamine antibacterial agents have been extensively studied for their unique structure and the ability of high efficiency in killing bacteria.But,they are seriously affected by ultraviolet rays,and the antibacterial performance is not long-lasting.Schiff base compound has unique chemical structure,is a novel antimicrobial agent with broad spectrum of biological activity.And its antimicrobial activity is not affected by ultraviolet radiation.It is of great application value to introduce Schiff base into the preparation of halamine to synthesize a new type of compound antibacterial agent.Based on this,a kind of hydantoin-based haloamine precursor 1-((4-(allyloxy)benzylidene)amino)imidazolidine-2,4-dione(AOBYID)containing Schiff base was synthesized in this thesis.The aromatic structure of AOBYID can protect the halamine bond.The aromatic structure of AOBYID itself can protect the haloamine bond.And the Schiff base functional group is helpful to improve the haloamine precursor's antibacterial effect.But hydantoin is not an antibacterial monomer.In order to obtain higher antibacterial activity,a triazole-based haloamine precursor N-(4-(allyl)benzylidene)-1H-1,2,4-triazol-3-amine(NABTA)containing Schiff base was synthesized by antibacterial monomer triazole.However,the solubility of two halamine precursors containing Schiff base is poor.In order to improve the solubility and maintain high antibacterial activity,a Schiff base-containing piperazine halamine precursor N-(4-(allyl)benzylidene)-2-(piperazine-1-yl)ethylamine(NABPE)was synthesized through the antibacterial monomer piperazine.AOBYID,NABTA and NABPE are respectively used for the antibacterial finishing of cotton fabrics.The antibacterial and washing resistance properties of the treated fabrics were studied.The main research results are as follows:1.Characterization and antibacterial activity analysis of Schiff base-halamine compoundsThese products were confirmed is that the object compounds AOBYID,NABTA and NABPE via the nuclear magnetic resonance(NMR)and infrared spectroscopy(FTIR).The minimum inhibitory concentration(MIC)was used to evaluate the antibacterial activity of the target compounds,and the MIC of AOBYID against E.coli and S.aureus were 2.25 g/L and 2.25 g/L,the MIC of NABTA were 1.875 g/L and 1.875 g/L,and the MIC of NABPE were 4 and 2 g/L,all of which showed good antibacterial activity.2.Study on antibacterial finishing and performance of cotton fabrics based on Schiff base-halamine compoundsFirstly,Raman and FTIR results showed that the success of MPTES modification and AOBYID grafted mercapto-modified cotton.The antimicrobial performance test results showed that the bactericidal rate of AOBYID finishing fabric against E.coli and S.aureus is 78% and 89%;the sterilizing rate of the AOBYID treated-chlorinated cotton was more than 99% after 5 min contacted with bacteria,and the sterilization rate of S.aureus reaches 100%.After 10 washing cycles,the sterilization rates of the chlorinated cotton against E.coli and S.aureus remained at78.71% and 80.70%.In addition,the AOBYID finished fabric showed good thermal and mechanical properties.Then,antibacterial cotton fabrics are produced by NABTA.The antibacterial performance test determined that NABTA treated fabrics have antibacterial rates of 89.58% and 88.80% against E.coli and S.aureus.The antibacterial properties of the halogenated fabric were enhanced by the synergistic effect of Schiff base and haloamine compound,which can kill 96.95% E.coli and 97.64%S.aureus within 1 min,and reached to 100% in 5 min.The antibacterial effect is better than that of AOBYID treated fabrics.In addition,41% of active chlorine was still retained after 50 cycles of washing,and the content of active chlorine was still 46% after 20 days storage,and 34% after 24 hours of UV irradiation,so good washing stability,storage stability and UV light stability.Finally,NABPE was used as antibacterial agent for cotton fabric's functional finishing.It was found that the introduction of piperazine not only improved the water-solubility,but also further enhanced the antibacterial properties of the finished fabric.NABPE-modified cotton fabrics have antibacterial rates of 94% and 93% for E.coli and S.aureus,respectively.NABPE-modified cotton fabrics have bactericidal rates of over 99% for E.coli and S.aureus after chlorination treatment(1min contact with bacteria),and 5 min can kill all bacteria.After 25 washing cycles,the antibacterial fabric still maintains high sterilization rates of 91.95% and 92.15% against E.coli and S.aureus;after 21 days of storage,it still retained 0.41 wt.% of active chlorine;after repeated chlorination and reduction treatments;and after repeated chlorination and reduction treatment,the active chlorine content of the treated fabrics was also maintained well.In addition,the antibacterial mechanism of Schiff base haloamine finishing fabric was analysed and confirmed that is contact killing bacteria.