Interferometric investigation of the opto-mechanical and structural properties of iPP/TiO2 nanocomposite fibers

Fibers that missing specific features and functionalities could be innovated and functionalised via nano additives, in particular metal oxides. Titanium oxide (TiO2) nanoparticles have been added to isotactic polypropylene (iPP) to form iPP/TiO2 nanocomposite fibers. Three samples of iPP/TiO2 fibers were extruded at three extrusion speeds 25, 50, and 78 m/min were considered in this study. Mach–Zehnder interferometer was used to assess the changes in the opto‐mechanical and geometrical parameters of iPP/TiO2 nanocomposite fibers along the fiber axis. The mechanical drawing device along with Mach–Zehnder interferometer was utilized to stretch the filaments to different draw ratios. The effect of mechanical cold drawing and extrusion speed on the optical and physical characteristics of iPP/TiO2 nanocomposite fibers were determined along the fiber axis. The optical and physical variation along the nanocomposite samples were characterized by measuring their refractive indices, birefringence, refractive index profile along the fiber axis. The diffraction of He–Ne laser beam was used to define the variation of the fiber diameter along the fiber axis through their cross‐sectional area and shape. A sample of uniform diameter from neat iPP fibers was used as reference material for studying the variation of the iPP/TiO2 fiber diameter along the fiber axis. As result, the iPP/TiO2 nanocomposite fibers exhibited nonuniform diameters. The dispersion of TiO2 particles in nanocomposite fibers influences the properties' consistency along and across the fiber

Interferometric Studies for the Annealing Effects on the Necking Deformation along Polypropylene Fibers

An automated multiple-beam Fizeau fringes in transmission technique was used with a fiber-drawing device to detect necking deformation along polypropylene (PP) fibers axis under different conditions of annealing process. The refractive indices, refractive index profiles and crystallinity were calculated along the annealed PP fibers at different draw ratios. The annealing temperature controls the propagation of necking deformation along PP fibers axis that stretched at low draw ratios (D< 2). The necking deformations along PP fibers axis due to fast drawing process could be avoided when PP fibers were annealed at the temperature of 120oC. Microinterferograms are given for illustrations