Study On The Preparation And Application Of Flame-retardant, Anti-bacterial And Hydrophobic Organic Silicon Functional Additives For Cotton Fabrics

Pure cotton is an important textile material.Cotton fabrics have excellent air and moisture permeability.But cotton fabrics are flammable and easy to breed bacteria.There are limitations in their application.Therefore,it is necessary to carry out flame retardant and antimicrobial finishing on cotton fabrics to give them flame retardant and antimicrobial properties.Flame retardant and antimicrobial finishing of cotton fabrics has always been a research hotspot,and is proceeding in the direction of high efficiency,safety and environmental protection.Based on this,a series of silicone flame retardants and antimicrobial agents for cotton fabrics have been synthesized and applied to cotton fabrics,and some results have been achieved.Three siloxane compounds with different functions were synthesized by linking functional flame retardant antimicrobial groups with potassium tetramethylcyclotetrasilanol?KCTSi?:?1?KCTSi reacted with piperazine and phosphorus oxychloride to prepare synergistic flame retardant hydrophobic agent PNCTSi containing silicon,phosphorus and nitrogen;?2?KCTSi reacted with piperazine and dicyandiamide to prepare cyclic organosilicon flame retardant antimicrobial GNCTSi containing multiple guanidines;?3?KCTSi reacted with piperazine,phosphorous acid and urea to prepare phosphorous cyclic siloxane ammonium salt flame retardant APCTSi.The structures of the three compounds were characterized by FTIR,¹HNMR and ¹³CNMR,which indicated that the three compounds were successfully synthesized.?1?The PNCTSi was dissloved by 50% acetone aqueous solution,cotton fabrics were treated by 250 g/L PNCTSi solution.The LOI value of PNCTSi-cot was 29.8%.The treated cotton fabrics had no after-flame and no after-grow by vertical burning test.The TG results showed that the treated cotton fabrics had higher thermal stability and higher carbon residue rate than pure cotton fabrics.The CA test was 150°,and the treated cotton fabrics had good flame retardancy and hydrophobicity after repeated washing.Expansion and bubbling on the surface of treated cotton fabric residue were observed by SEM.The above results show that PNCTSi is a good hydrophobic agent and intumescent flame retardant for cotton fabrics.?2?The GNCTSi was dissloved by 50% isopropanol aqueous solution,cotton fabrics were treated by 250 g/L GNCTSi solution.The LOI value of GNCTSi-cot was 30.1%.The length of residual carbon was 6.5 cm with no after-flame and no after-grow.TG test showed that the residual carbon rate of treated cotton fabrics was significantly higher than that of pure cotton fabrics.The results of antimicrobial test showed that the treated cotton fabrics had excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus.SEM test showed that the surface of cotton fabric residue was covered by silica,and the mechanical strength of cotton fabrics did not change significantly.The above results show that GNCTSi is an excellent flame retardant and antimicrobial agent for cotton fabrics.?3?APCTSi was dissolved in water as finishing solution.Cotton fabrics treated with250 g/L APCTSi finishing solution.By LOI,vertical burning test and thermogravimetric test,APCTSi-cot showed superior flame retardancy.SEM test showed that the treated cotton fibers were covered by oil film.The cotton fiber residue had bubbled structure of expansion and rupture.The above results show that APCTSi is an excellent synergistic flame retardant of silicon,phosphorus and nitrogen.