A Technological Study On Non-aqueous Soaping Of Reactive Dyes

D5(Decamethyl Cyclopentasiloxane) is a oily, volatile, odorless andcolorless ring silicone compound, which has been proven to be a safe andenvironment-friendly compound. Cotton fabric could be dyed in deep shadewith reactive dye in dye/D5suspending system without adding salt. The dyeup-taking was close to100%, total fixation was very superior to that in aqueoussystem, and D5can be recycled and reused after dyeing.Although, by this technology, water consumption for dyeing could bereduced, but in the soaping process after dyeing, a large amount of water stillneeded as medium, which weakens the advantage of the non-aqueous dyeingwith D5. If D5can be used not only as dyeing medium but also as soapingmedium, the new dyeing technology will be more viable and effective.Firstly，the research focuses on the feasibility of D5soaping for cottonfabric dyed in aqueous dye bath. Then, D5soaping for cotton fabric dyed inreactive dye/D5suspension system was also investigated and the processparameters were optimized to establish and improve the soaping technologyCotton fabric dyed by2%(o.w.f)reactive dye with160%pick-up was soapedin D5bath under following conditions:, soapingagent(N-Polyoxyethylated-N-octadecylamine):1.5g/L,m(fabric):m(D5):m(water)=1:50:3,time:10min,temperature95℃, obtaining a good soaping effect, with thecolor fastness meeting the generic requirement of textile. But soapingefficiency was only62%, much lower than88%of water soaping.Anyway，itshowed the way to establish the similar method in the application of D5soaping matched to reactive dye/D5suspending system dyeing technology.Applied cotton fabric dyed in1%（o.w.f） reactive dye/D5suspendingsystem into the D5soaping research,used the same method as aqueous dyeingcotton fabric soaping in D5.Compared the soaping efficiency between D5dyeing/soaping and aqueous dyeing/soaping.The soaping efficiency is84.7%:91.5%,the D5soaping still needed progress,but the textile fastness has met thetextile fastness standard.Optimized the process of soaping reactive dye/D5suspending systemdyeing fabric in D5,the result is:agent(N-Polyoxyethylated-N-octadecylamine):2g/L,m(fabric):m(D5):m(water)=1:20:2,time:10min,temperature95℃.The soaping efficiency was increased to85.7%, and most fastness index reached the standard,but it had saved cost andenergy because of the decrease of D5and water.In order to get the better effect,tried to do the D5soaping twice Keep theother options fixed, add water two times,m(fabric):m(water)=1:1eachtime.Doing this,got the91.8%soaping efficiency which beyond the traditionalmethod in water91.5%.The soaped fabric fastness index is close to traditionalmethod,too.The maximum absorption wavelength of cotton fabrics dyed with reactivedyes in D5system were determined, it turned out that D5has no effect on colorshade of reactive dyes. Further, more analysis such as IR, AEM, TG, XRD, aswell as tensile strength testing were carried out, in consequence, dyeing andsoaping in D5system have almost no effect on fiber’s chemical structure,appearance, thermostability, crystallinity and mechanical properties.The D5soaping process has been proven to be feasible and can be the match technologyof reactive dye/D5suspending system.