| The purpose of this study was to characterize the dyeing behavior of polyester filament yarns given a high-temperature solvent pretreatment based on two conventional models of dye diffusion: the free volume model, which is generally accepted for synthetic fibers, and the pore model, which is applied to porous materials such as cellulose.; The dyeability of the solvent-treated polyester was much greater than that of untreated yarns, as evidenced by liquid chromatography work, uptake measurements using methanol as a dye solvent, and microscopical examination of fiber cross-sections containing a fluorescent dye. Quantitative studies of dye uptake and diffusivity showed that the solvent treatment lowered the fiber's glass transition under dyeing conditions and that, above this temperature, free volume diffusion was dominant. Limited dyeability below the glass transition was taken as evidence of the creation of pores by the solvent treatment. |
