Abstract: | In the current study, in order to prepare poly(ethylene terephthalate) (PET)/organoclay nanocomposite fibers, a slurry‐compounding method (SCM) was applied and compared to conventional melt‐compounding method (CMM) in terms of the dispersion of organoclays and the performance of the spun and or drawn fibers. The organoclays were synthesized by using three different alkyl phosphonium salts and compared with commercially available alkyl ammonium‐modified organoclays in terms of thermal stability and basal spacing. It was found that the alkyl phosphonium salts exhibited higher thermal stability and basal spacing with respect to commercial alkyl ammonium organoclays. Among them, tributylhexadecylphosphonium bromide resulted in superior properties; therefore, it was used to prepare the nanocomposite PET fibers. The organoclay content of 0.1–1 wt% was taken as the material parameter. It was demonstrated that the SCM yielded better dispersion of organoclays with respect to CMM. The drawn nanocomposite fibers prepared via SCM exhibited improved tensile strength and modulus in comparison to the neat‐PET. The maximum tensile properties for fibers were obtained at 0.5% organoclay loading in SCM. The thermal properties and the percentage of crystallinity were investigated by differential scanning calorimetry analysis. In addition, Fourier transform infrared spectroscopy was utilized to obtain the percentage of crystallinity of the fibers. POLYM. COMPOS., 34:887–896, 2013. © 2013 Society of Plastics Engineers |