Effect of montmorillonite on the oxidative stability of polyphenylene sulfide fibers prepared by melt spinning

Abstract

Masterbatches of polyphenylene sulfide (PPS)/organic montmorillonite (MMT) composites were produced via melt blending. A self-made spinning equipment was then used to produce the PPS/organic MMT composite fibers by melt spinning directly from the masterbatches. X-ray diffractometer and transmission electron microscope were used to examine the dispersibility of organic MMT. The morphology, tensile property, crystallization behavior, and oxidative stability of PPS fibers were investigated. The results indicated that organic MMT could be uniformly distributed in the PPS matrix to form a mixed dispersion of intercalated and exfoliated structure and influence the longitudinal surface morphology of fibers to become rough. The roughness of composite fibers surface was proportional to the content of organic MMT. The organic MMT nanolayers could act as the heterogeneous nucleating agents to improve the crystallization, and the crystallity of composite fibers increased with the increase of organic MMT content. The breaking strength of composite fibers first increased and then decreased by increasing the amount of organic MMT. After the oxidation treatment, the breaking strength of neat PPS fibers and composite fibers declined, but the degree of breaking strength loss for composite fibers is lower than that of neat PPS fibers. The dynamic oxidation induction temperature of composite fibers also showed a significant increase by adding organic MMT. Moreover, the addition of organic MMT could limit the chemical combination of element sulfur and oxygen, retard the generation of sulfoxide groups, and induce the conversion of sulfur atoms from C-S bond to sulfone for improving oxidative stability.