Alkali-hydrolysis kinetics of alkali-clearable azo disperse dyes containing a fluorosulphonyl group and their fastness properties on PET/cotton blends

The alkali-hydrolysis kinetics of a series of 4-amino-4′-fluorosulphonylazobenzene disperse dyes were investigated using HPLC and their fastness properties on PET/cotton blends were examined. Most of the dyes showed reasonable level of hydrolysis (%) under relatively mild alkaline condition and the dyes having more electron-accepting group in diazo component exhibited lower rate of hydrolysis. The application of fluorosulphonyl containing disperse dyes on PET/cotton blends showed excellent dyeing fastness properties and offers the option of one-bath dyeing process, replacing time- and energy-consuming conventional two-bath dyeing process.