“Foil spintrusion” of high‐performance polymer films

Abstract

AbstractThis article describes the development of high‐performance polymer foils by direct orientation in the liquid‐crystalline phase of a thermotropic copolyester, based on p‐hydroxybenzoic acid (HBA) and 2‐hydroxy‐6‐naphthoic acid (HNA), better known under the trade name Vectra®. Application of a simple air‐gap‐filament‐fusion‐extrusion process (“foil spintrusion”) with the use of a newly developed die, results in highly oriented free‐standing foils, as thin as 3 μm. These foils have a mechanical performance that is comparable with those of commercially produced fibers of the same material. These uniaxially oriented foils could be laminated upon hot‐compacting without, or with as little as 5 wt % of an adhesive, yielding planar foils as thin as 18 μm, which feature excellent isotropic, in‐plane mechanical properties, that is, a Young's modulus E = 20 GPa and a tensile strength σ = 0.5 GPa. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012