Cover Image, Volume 50, Issue 24


original image

The cover depicts an as-spun high-performance polymer foil of a thermotropic copolyester, known under the trade name Vectra, viewed between crossed polarizers, as presented on page 1713 by Jérôme Lefèvre, Kirill Feldman, Jan Giesbrecht, Paul Smith, Theo A. Tervoort, and Han E. H. Meijer. The high degree of uniaxial orientation, evidenced by the birefringent image, is due to the application of a simple air-gap-filament-fusionextrusion process (“foil spintrusion”) with the use of a newly developed die, and results in a mechanical performance of the foils (modulus 60 GPa, strength 1 GPa) that is comparable with those of commercially produced fibers of the same material.