Poly(ethylene terephthalate)/poly(ethylene-co-vinyl alcohol) sheath-core fibers: preparation and characterization

Abstract

Abstract A novel sheath-core poly(ethylene terephthalate) (PET)/poly(ethylene-co-vinyl alcohol) (EVOH) composite fiber was designed and manufactured to improve the hydrophilicity of the PET fibers. The thermal stability of EVOH was first examined to determine the possible processing temperature. Second, the rheological characteristics of EVOH were measured to obtain the appropriate spinning parameters. Then, PET/EVOH composite fibers with various sheath-core ratios were manufactured and the effect of sheath-core ratio on the stable spinning process was investigated. Scanning electron microscopy (SEM) shows that the PET/EVOH fibers possess a round sheath-core cross-section and a smooth surface, indicating successful spinning. Finally, the mechanical properties and moisture absorption of the PET/ EVOH composite fibers were measured. For PET/EVOH composite fibers, the PET content contributes to the mechanical properties and the EVOH content contributes to the moisture absorption. For the PET/EVOH composite fibers with a sheath-core ratio of 50:50, the moisture regains at room conditions reach to 2.8% and the breaking strength is 2.53 cN/dtex. These good mechanical and moisture properties attract good application prospects.