The effect of structural changes on dye diffusion in poly(ethylene terephthalate)

Abstract

Abstract The diffusion of a disperse dye, 1‐amino‐4‐hydroxyanthraquinone (C.I. Disperse Red 15) into poly(ethylene terephthalate) fibers has been studied as a function of heatsetting temperature and draw ratio. It was found that the dynamic loss modulus E ″, measured under the dyeing conditions, was related to the dye diffusivity D . This indicates that the diffusion is controlled by the mobility of the polymer chain segments. Both the diffusivity and dye saturation values do not vary monotonically with heatsetting temperature but exhibit a minimum at a heat‐setting temperature near 175°C. X‐ray diffraction measurements were used to show that this behavior is attributable to crystallinity and crystal size changes resulting from heat‐setting.