Dyeing Of Polysulfonamide Fabric With Carrier Sa

Polysulfonamide (PSA) fiber is a kind of aramid fiber and its thermal stabilization is very good. There are aryl groups, 1amido groups and sulfone groups in the main chain of its macromolecule. PSF is difficult to obtain a satisfactory dyeing depth because of its high glass transition temperature (Tg), compact molecular structure and strong intermolecular cohesion between polymer and its congeries. Now the methods to dye PSF include high-temperature-high-pressure dyeing with disperse dyestuffs, carrier dyeing with disperse or cationic dyestuffs, and dyeing after pretreating PSF with swelling agent. The fabric obtains light color and dark luster when dyed with disperse dyes. While dyed with cationic dyes, the fabric has a bright color. Acetophenone is an efficient carrier applied in dyeing PSF, but it remains irritant odor on the dyed fabric. The dyeability of PSF is improved by dyeing after pretreating PSF with swelling agent, but the dyed PSA fabric has a large shrinkage.Basing on dyeing after pretreating PSF with swelling agent, the research was focused on reducing the dyed fabric shrinkage. A low-toxicity and lowly-irritant carrier Sa was also applied in dyeing PSF. Pretreating the tight PSA fabric with swelling agent SW-A, SW-B, or SW-C not only avoided its shrinkage in pretreatment but also reduced its shrinkage in dyeing. Washing after pretreatment was also beneficial to reducing shrinkage of the fabric in dyeing, but the K/S value fell mildly.After being pretreated with swelling agent SW-B, the tight PSA fabric was relaxed, washed and dyed with MAXILON Red SL 200%(2%, o.w.f). The shrinkage rate of the fabric was 5.25% and its K/S value was 21.985. Carrier Sa could also improve the dyeability of PSA fabric obviously. The optimized dyeing condition with carrier Sa was that dyeing temperature was 100℃and the concentration of carrier Sa was 9% (o.w.b). The fabric’s shrinkage rate was 15.22% and its K/S value was 24.013 after PSA fabric was dyed on the optimized dyeing condition with MAXILON Red SL 200%(2%, o.w.f). When PSA fabric was dyed with carrier acetophenone, the fabric’s shrinkage rate was 16.30% and its K/S value was 22.888.After being pretreated with swelling agent SW-B, the tight PSA fabric was relaxed, washed and dyed with carrier Sa(4%, o.w.b) and MAXILON Red SL 200%(2%, o.w.f). The shrinkage rate of the fabric was 7.84% and its K/S value was 24.937, however the fabric’s handle was hard. Compared with the other dyeing methods, dyeing with carrier Sa could obviously improve the dyeability of PSA fabric. Its K/S value of dyeing with cationic dyes was only lower than that of the fabric dyed with carrier Sa after the tight fabric was pretreated with swelling agent SW-B and washed. The K/S value of dyeing with disperse dyes was higher adversely. The shrinkage rate of the fabric dyeing with carrier Sa was only higher than that of the fabric dyed with carrier acetophenone. But dyeing with carrier Sa also had other advantages, for example carrier Sa had low toxicity and irritant odor, dyeing process was simple and convenient, there was no irritant odor remaining on the dyed fabric, etc.The optical microscope picture of the PSF cross section indicated that the dyestuffs penetrated equally in the fibre dyed via carrier Sa. The colorfastness to washing and rubbing was above 4. And the colorfastness to light was about 3. The SEM picture of the longitudinal configuration indicated that the surface of the fiber treated with carrier Sa was not etched obviously. The X-ray diffraction indicated that the crystallinity of fiber increased by 3.39% after treatment with carrier Sa. The tensile strength of the fabric or yarn treated with carrier Sa decreased obviously. The TGA test indicated that the main chain of PSA macromolecule was not broken by carrier Sa in dyeing, and carrier Sa just swelled the PSF. The DSC test indicated that the glass transition temperature of PSF was reduced by carrier Sa in dyeing. ##无编改内容...