Sensitivity Analysis Of Vynyl Sulphone And BisMonochlorotriazine Reactive Groups Of Reactive Dyes

European Scientific Journal June 2016 edition vol.12, No.18 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 Sensitivity Analysis Of Vynyl Sulphone And BisMonochlorotriazine Reactive Groups Of Reactive Dyes Sanjida Sultana Primeasia University, Dhaka, Bangladesh Dr. Ummul Khair Fatema Bangladesh University of Textiles, Dhaka Bangladesh Md. Aminul Islam Huntsman Pte Ltd, Singapore doi: 10.19044/esj.2016.v12n18p337 URL:http://dx.doi.org/10.19044/esj.2016.v12n18p337 Abstract Reactive dyes contain different types of reactive groups which have different levels of sensitivity. Reactive dyeing is carried out by exhaust method on cotton knit fabric. A trichromatic combination is chosen containing vinylsulphone and bis-monochlorotriazine reactive groups. Dyeing of fabric is carried out with standard condition and variation of the conditions (electrolyte concentration, pH, exhaustion time, fixation time and M:L). Colorimetric data (DE*) is produced by comparing the difference between standard shade and the resulting shades by using spectrophotometer. Between the investigated reactive groups of reactive dye bismonochlorotriazine shows lower sensitivity in other terms higher robustness than vinyl sulphone. Keywords: Sensitivity, Reactive monochlorotriazine, Exhaust dyeing dye, Vinylsulphone, Bis- Introduction Colour of textile is one of the most important quality parameter required by the customer. But it is very difficult to achieve according to standards even with the support of modern colorimetric system and computer colour matching due to the complexity of the dyeing processes. Among all dyes reactive dyes are mostly used for dyeing cotton substrate. Reactive dyes contain different types of reactive groups which are important for dyeing because they are sensitive to different variables of dye-bath to different extent. The sensitivity causes color difference due to any change of variables (like pH, electrolyte concentration, temperature, time, M:L, etc.). This 337 European Scientific Journal June 2016 edition vol.12, No.18 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 sensitivity is reciprocal of robustness (correctness) where robustness is defined as the dispensing error that would produce a color difference of one unit between the correct recipe and incorrect recipe (McDonald, 1997). It follows that highly sensitive recipes are not very robust and hampers right first time to be produced. Should dyeing errors occur, the less sensitive the recipe to such errors, the more chance there is that the resultant shade will be successful (Monsoor, 2012). The goal of this work is to help the exhaust dyer to select the right recipe for higher production with lower sensitivity and higher robustness. The exhaustion and fixation of reactive dyes depends on sensitivity of reactive groups and are determined by number of factors. The most important factors are: the pH of dye bath, the temperature of dyeing, concentration of electrolyte, the time of dyeing and the material to liquor ratio. Among the investigated reactive groups vinyl sulphone is monofuctional and bis-MCT is bi-functional. The general structure of vinyl sulphone reactive dye is as follows: The reactive group that has had the greatest impact on the market is the 2-sulfooxyethylsulfonyl group (Klaus, 2003). Treatment with alkali in this case causes the elimination of sulfuric acid to form a vinylsulfonyl moiety that reacts with cotton to give a dye-fiber bond. This has an elimination-addition sequence. Reaction 1: Covalent bond formation between vinyl sulphone reactive dye and cellulosic fibre, where D= Chromophore. Crom. - SO2-CH2-CH2-X + Alkali → Crom. – SO2- CH= CH2 + HX Where, X = OSO3H, Cl Reaction 2: Vinyl sulphone dye formation from 2-chloroethylsulfonyl derivatives. 338 European Scientific Journal June 2016 edition vol.12, No.18 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 Reactive vinyl sulphones are also prepared from 2chloroethylsulfonyl derivatives, which lead to the desired intermediates by elimination of hydrogen chloride (Klaus, 2003): Numerous derivatives of ethylsulfonyl and vinylsulfonyl groups have been prepared in recent years, though none have approached the economic importance of the sulfate esters. These dyes have medium reactivity and lower substantivity (Clariant, 2002). Exhaust dyeing temperatures between 40°C and 60°C may be chosen, depending on pH (John, 1995). These dyes are applicable by a wide variety of batch wise and continuous processes (John, 1995). In case of bis-MCT reactive group, two monochlorotriazine units are connected by a suitable bridge (Clariant, 2002).. Structure 2: General structure of bis-monochlorotriazine Reactive Dye (Klaus, 2003). The synthetic approach to these compounds makes it possible to combine two different chromophores in a single system, opening the way to certain color shades that are not easily accessible via a single chromophore (Klaus, 2003). Procion HEXL dyes were designed to have substantially increased substantivity, exhaustion and fixation values compared with corresponding products carrying only one chlorotriazinyl group. The triazinyl group readily lends itself to substantivity enhancement and this property, together with an application temperature of 80°C, was used to facilitate good exhaustion and outstanding leveling properties. This approach led to improved colour utilization and in turn to less colour in the effluent (Renfrew, 1999). Reactivity of bis-MCT dye is low and the substantivity is high (Clariant, 2002). The additional technical features offer improvements in robustness and reproducibility. 339 European Scientific Journal June 2016 edition vol.12, No.18 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 Reaction 3: Reaction involved in bond formation between bis-MCT reactive dye and Cellulose. Experiment: Materials & Method 100% Cotton scoured and bleached single jersey knit fabric of 180 GSM was used. Lab grade chemicals of Glauber’s salt (Na2SO4.10H2O) of 95% purity, Soda ash (Na2CO3) of 98% purity, Acetic acid (CH3COOH) of 98% purity were purchased from Merck LTd, Germany. Lab grade chemicals of Eriopon R (Sodium salt of a modified polyacrylic acid) which is a soaping agent was purchased from Huntsman Pte, Ltd. Singapore. Table 1: Investigated reactive groups of reactive dye Functionality Reactive Group Reactive dye Brand name Manufacturer Monofunctional vinyl sulphone Remazol Yellow RR Remazol Dystar Homo bi-functional bismonochlorotriazine Remazol Briliant Red F3B Remazol Blue BB Procion Yellow HEXL Procion Crimson HEXL Procion Sapphire HEXL Procion Dystar Dyeing method: Exhaust dyeing method was used for dyeing cotton fabric. 0.3% shade was dyed for light shade and 2.1% shade was dyed for dark shade. Table 2: Recipe of dyeing of cotton fabric with VS reactive dye (Light shade) Dyes/Che micals Remazol YellowR R Remazol Brilliant Red F3B Sampl e1 (Stand ard) 0.1% owf 0.1% owf Sam ple 2 Sam ple3 Sam ple 4 (...truncated)