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Linen fabrics were cationized using 3-chloro-2-hydroxypropyl trimethyl ammonium chloride in alkaline medium. The cationized linen fabrics were dyed independently, with different dyestuffs, namely reactive, direct and acid dyes in absence of salt (no-salt dyed). Factors affecting the nosalt dyeing process of cationized linen fabrics were investigated. These factors included dye concentration, pH of the dyeing bath, dyeing temperature and time as well as the chemical nature of the dyes used. The dyed samples were monitored for color strength (K/S) after soaping and after DMF extraction as well as fastness properties. It was found that for all dyestuffs used, the magnitude of K/S of the dyed samples depends on the nature of the dyes and the conditions used in each case. It was also seen that for no-salt dyeing of cationized linen fabrics, the maximum K/S was achieved at dye shade 2.5 % (ows) and dye bath’s pH 7-9, at 60°C for 20 minutes. In addition to this, the color strength was much higher in case of cationized and no-salt dyed samples compared with the uncationized and traditionally salt-dyed linen fabrics; meanwhile, the overall fastness properties were comparable. Microscopic examination of the cationized and no-salt dyed linen fabrics showed an excellent dye penetration and no evidence for the ring dye phenomena was observed.

Mill scoured and bleached linen fabrics were cationized using Quat-188. Cationization was carried out as per the exhaustion or the cold pad-batch technique under a variety of conditions. Factors affecting the cationization reaction of linen fabric were studied. These factors include Quat-188 concentration, NaOH concentration (or pH of the reaction medium in case of exhaustion method), reaction time and temperature as well as material to liquor ratio (in case of exhaustion method). The cationized samples were monitored for nitrogen content, and the reaction efficiency calculated thereof, as well as for K/S of the no-salt dyed samples. Results obtained indicate that the efficiency of cationization of linen fabric with Quat-188 depends on the type of application technique and the conditions used in each technique. Using the exhaustion technique, maximum reaction efficiency between Quat-188 and linen fabric was achieved at Quat-188, 80 g/1 and pH, 13 and 70°C for 60 minutes using material to liquor ratio, 1:20. Lower material to liquor ratio was not practically possible. The results also depict that any deviation from these conditions, for example, higher pH, temperature or material to liquor ratio, leads to an increase in the hydrolysis of Quat-188 molecules and hence, lower reaction efficiency. With the cold pad-batch technique, maximum reaction efficiency was achieved when the linen fabric was padded in a solution containing NaOH, 50 g/1 and Quat-188, 125 g/1, then squeezed to a wet pickup of 100% and batched for 15 hours. Results obtained also signify that both dry and wet wrinkle recovery angles increase as the degree of cationization (expressed as N % of cationized linen fabric) increases. Moreover, the tensile strength of cationized linen fabric is higher than that of uncationized linen and such an increase depends on the degree of cationization.

The synthesis and chemistry of nitrogen heterocyclic azo compounds have been extensively studied. Many derivatives of this type were proved to be excellent dyes. Presents a systematic and comprehensive survey of all recently synthesised nitrogen heterocyclic azo dyes according to dyeing methods.