Low-Modulus “Hard” Elastic Materials

Abstract

The application of “hard” elastic fibers as textile and industrial materials, where elasticity at large extensions and over a wide temperature range may be desirable, is impaired because of their relatively high initial modulus. This paper describes the preparation and evaluation of hard elastic fibers modified in such a way that low initial moduli become available. These hard elastic fibers, heat-set in the extended state, maintain high elastic recoveries, have moduli in the 1–10 g/den (1.11–11.1 dtex/den) range with tenacities between 1–4 g/den (1.1–4.4 dtex/den) and work recovery of over 70%. Methods of preparation and tensile evaluation are given. A model of the extension-retraction mechanism is proposed based on small-angle x-ray diffraction data.