Isotherms and kinetics of dyeing poly-m-phenyleneisophthal-amide with Basic Red 46 based on the macro-cation dyeing mechanism

The aggregation behaviors of Basic Red 46 in water, water/dimethylacetamide (water/DMAc), and water/DMAc/NaCl were investigated by both a Transmission Electron Microscope and a laser particle size analyzer. The corresponding electric conductivity of the dyeing solution and surface zeta potential of dye aggregates using different concentrations of DMAc and NaCl were compared. The kinetics and adsorption isotherms of dyeing poly-m-phenyleneisophthalamide (MPIA) based on the macro-cation dyeing mechanism were investigated. The Langmuir and Freundlich models were used to determine the adsorption type. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to determine the kinetics of [DMAc-Dye]+ adsorption onto MPIA. The washing and rubbing fastness of dyed MPIA using different initial dye concentrations and dyeing time were measured and analyzed.