Spinnability and Tensile Properties of Poly(ethylene terephthalate) Fibers Blended with Polymeric Ionic Liquids in Melt Spinning Process

Ionic liquids (ILs) with unique properties such as low melting point, high thermal stability, electrical conductivity, good solubility etc. are widely used as the environment-friendly solvents. Studies show that the use of ionic liquids is a new effort in textile industry and basic research, as these are applied as green solvents in solution spinning of the viscous fibers in industrial scale. In this study, blending of some polymeric ionic liquids (PIL) with poly(ethylene terephthalate) (PET) was examined by melt spinning process to produce PET/PIL fibers. Also the mechanical properties of the melt spun fibers were evaluated. The results showed that addition of polymeric ionic liquids to PET during the melt spinning process would cause complications due to high moisture absorption and hydrolysis of PILs. The melt viscosity of PET/PILs in melt process dropped significantly. The viscosity reduction of the blends was prevented using a polymeric chain extender. Also the cationic laurylurethane trimethylene was considered an appropriate polymeric ionic liquid which showed the lowest adverse effect on the mechanical properties of PET/PILs fibers in an optimized composition.