Thermoplastic PolyUrethane fibers filled with multi-walled carbon nanotubes: relationships among fiber draw ratio, filler content and performances of epoxy based items

The research is aimed to investigate the influence of draw ratio of thermoplastic polyurethane based fibers filled with multiwalled carbon nanotubes on the final properties of epoxy based products reinforced by the same. In more details, extruded compounds were melt spun using a spinning line to make nanocomposite fibers with two draw ratios properly named as low and high draw ratio fibers and with nanotube loadings equal to 0.2, 1, 3 and 5 wt%. These latter, opportunely analyzed especially in terms of tenacity and viscoelastic behavior, were subsequently employed to reinforce a bi-functional epoxy resin. At this regard, with the help of a mold designed ad hoc, preliminary investigations have been performed on samples derived from plaques of a typical epoxy resin: Diglycidyl ether of bisphenol-A, in which a certain number of fibers were disposed parallel. The influences of fiber draw ratio and their filler content on performances of produced epoxy composites were assessed by tensile, flexural and three-point bending dynamic tests.