Effect of the uniaxial orientation on the polymer/filler nanocomposites using phosphonate-modified single-walled carbon nanotube with hydro- or fluorocarbons

The effect of drawn orientation on crystalline fluorinated polymer/carbon nanotube nanohybrids was investigated. Single-walled carbon nanotubes (SWCNTs) were surface-modified with long-chain phosphonic acids, thus imparting heat-resistant/non-desorption properties. Polyvinylidene fluoride (PVDF) was used as the crystalline fluorinated polymer and a polypropylene (PP) matrix as the crystalline hydrogenated polymer, for comparison. In the nanocomposite preparation, PVDF was combined with phosphonic acid-modified SWCNT containing fluorocarbon chains, and PP was combined with phosphonic acid-modified SWCNT containing hydrocarbon chains. Nanocomposite preparations of organo-SWCNTs with an affinity for the polymer matrix were achieved by a simple melt-compound method. These nanocomposites were uniaxially drawn at high temperatures near its melting point, and the organo-SWCNTs were aligned in the polymer matrix along the drawn direction. The lamellae in the fluorinated polymer-based nanohybrids were aligned parallel to the drawn direction at 5 × drawing, and converted to a herringbone arrangement with a left–right tilting at 7 × to 9 × drawings. As a result, it was clarified that the addition of a small amount of SWCNT leads to an improvement of crystallinity, crystallization temperature, lamella thickness, and mechanical properties of the nanocomposites. Graphic abstract