Influence of hydrolysis of reactive dye on dyeing property of cotton fabrics

Cotton fabrics were dyed with hydrolyzed and unhydrolyzed Reactive Bright Red X-3B,respectively.The dyeing properties of modified and unmodified cotton fabrics were investigated by testing the absorption spectroscopy of hydrolyzed and un-hydrolyzed active dye solution and the color indexes(L*,a*,b*and c*values) and K/S values of the dyed fabrics.It was found that the differences of the UV-Vis absorption spectroscopy of dye solution between hydrolyzation and unhydrolyzation were very large and the colour of dye solution was light when the reactive dye was hydrolyzed.The uptake and fixation of the dye,and the colour and K/S values of the dyed fabric were influenced by the hydrolyzation of dye.The dyeing properties of both hydrolyzed and unhydrolyzed dyes on the cotton fabrics after reactive and non-reactive cationic modification were improved.Reactive modifiers significantly enhance the uptake and color fixation rate of hydrolyzed and unhydrolyzed reactive dyes on cotton fabrics,especially the color fixation rate.