Dyeing kinetics of acid dyes onto soybean/casein/polyvinyl alcohol and soybean/polyvinyl alcohol blend fibers

Two acid dyes C.I. Acid Blue 113 and C.I. Acid Blue 168 were applied to soybean/casein/polyvinyl (SCP) alcohol blend fibers and soybean/polyvinyl (SP) alcohol blend fibers, and the dyeing kinetics of two fibers were compared. Three kinetic equations, namely Chrastil, Cegarra-Puente and Vickerstaff, were used to fit the experimental dyeing rate points, showing that the best result was obtained by the Chrastil equation. Due to the ratio of acidic amino acids and basic amino acids for SCP was lower than SP fibers, the amino group amount of SCP fibers was higher than that of SP fibers. So SCP fibers displayed slightly higher dyeing rates and dye adsorption values at equilibrium stages than SP fibers. Furthermore, the dyeing of SCP fibers exhibited lower activation energies and higher dyeing rate constants than that of SP fibers and therefore showed slightly lower dependence on temperature.