Thermodynamic parameters of disperse dyeing on several polyester fibers having different molecular structures

Dyeing properties of the easy dyeable polyester (EDP) and the polytrimethylene terephthalate (PTT) were investigated in terms of their thermodynamic and kinetic factors, such as standard affinity (−Δμ0), enthalpy change (ΔH0), entropy change (ΔS0), diffusion coefficient (DT) and activation energy of the diffusion (ED). The results were compared with corresponding properties of the PET (polyethylene terephthalate). The −Δμ0 of the EDP and the PTT showed a little higher value than that of the PET. PET displayed the highest negative values of the ΔH0 and the ΔS0, while PTT showed the lowest negative values of them. For all three polyester types, as the temperature increased, the DT increased. PTT had the highest DT at every temperature and PET showed the lowest values of the DT. The ED of the EDP and the PTT was lower than that of the PET.