Cationic fiber reactive dyes for cellulosic fibers

The goals of this research were development of "zero electrolyte" fiber rea ctive dyes for cotton and simultaneous exhaustion and fixation of fiber rea ctive dyes for polyamide fibers. Two series of azo dyes were synthesized wi th varying electronic charge. In one series, a vinylsulfone (VS) group was incorporated into an azo chromogen. In the other series, a nonreactive ethy lsulfone (ES) group was incorporated into the molecule in lieu of the VS gr oup. The ethylsulfonyl moiety was a useful nonreactive analog of VS-based d yes. In the absence of electrolyte, the cationic fiber reactive dyes exhibi ted inherent substantivity for both cotton and nylon 6,6 under neutral or a lkaline pH. In certain cases, level dyeings were achieved with high exhaust ion and fixation levels. Cationic fiber reactive dyes offer potential for u se in environmentally responsible fiber reactive systems.