Abstract:

Based on the developed dyeing prototype, the kinetics of dyeing of polyester with C.I. Disperse Red 60 in supercritical CO2 was studied. The diffusion coefficient of the dye in PET in supercritical CO2 increases with the increase of temperature. The activation energy calculated with the Arrhenius equation is 22.22 kJ/ mol, which is far lower than the activation energy in traditional water dyeing process of 163.84 kJ/ mol. The thermodynamics of dyeing of polyester with C.I. Disperse Red 60 in supercritical CO2 was investigated. The uptake of C.I. Disperse Red 60 in PET fiber is linear to the dye concentration applied. The SC-CO2 dyeing is actually a distribution process of the dye between fiber and the fluid. The distribution coefficient and the thermodynamic affinity of the dye decreases with the increase of temperature. Both the enthalpy and entropy of dyeing are negatives, which is -23.63 kJ/mol and -26.18 J/(mol•K) respectively.