Polyethylene terephthalate (PET) fiber, which is a type of polyester fiber, is the most widely used as a synthetic fiber due to its good physical and chemical properties. It is also well known that PET fiber is dyed using disperse dyes with carrier or at high temperature (120-130°C), owing to its hydrophobic nature and highly compact molecular structure. To improve the physical and chemical properties of the polyesters fibers, the Polyester fibers can be modified. Heat setting is one of the methods to modify the Polyester fibers. Marvin in 1954 investigated the effect of thermal treatments on the dye uptake of polyester fibers. Dye uptake first diminished on increasing the heat-setting temperature up to 170-200, beyond which dye uptake increases in heat-setting temperature. Others workers Leube, Merian, Schreiner and Donze also have examined the influence of heat setting treatment on the dye uptake of polyester fibers. In this study polyester fibers was dry heat set at 160, 180, 200, 220?C, steam set at 100, 120?C and water set at 100, 130?C. The Polyester nano fibers produced by electrospining. Thermodynamic and kinetic parameters of dyeing on the heat set, steam set, water set polyester fibers at different temprature were investigated and compared with Nano polyester fibers. Thermodynamic and kinetic parameters such as standard affinity, enthalpy change, entropy change and diffusion coefficient were calculated. The results show that minimum standard affinity and maximum negative value of enthalpy and entropy change obtained for heat setting polyester at 160°C. As the temperature of heat setting is increased from 160°C to 220°C, the standard affinity is also increased. Also in the case of steam setting and water setting polyester fibers, as the temperature increased the standard affinity decreased. For all of the samples, as the temperature of dyeing increased the diffusion coefficient also increased. The standard affinity of polyester nano fibers were higher than PET. Keyword : polyester, setting, Thermodynamic, kinetic, parameters, temperature
