Relationship between Crystallization Behavior and Mechanical Performance of F-Ⅲ Fibers under Different Tensions in Supercritical Carbon Dioxide

摘要

In this article, the supercritical carbon dioxide (Sc-CO_2) was used as a medium for hot-drawing of F-Ⅲ fibers. The conditions of hot-drawing were selected to be the temperature of 250 °C, pressure of 14 MPa, time of 60 min, and different tensions, which were 0, 3, 4.5, 6, and 7.5 gd~(-1), respectively. All samples including the untreated and treated F-Ⅲ fibers were characterized by a mechanical tester and X-ray diffraction (XRD). Results showed that the Sc-CO_2 and applied tension could both promote the crystallinity and degree of orientation of F-Ⅲ fibers at a temperature below the Tg of F-Ⅲ fibers in Sc-CO_2. Moreover, compared with the untreated, the tensile strength and modulus of treated F-Ⅲ fibers tended to increase with the increase of tension in the range of 0~6 gd~(-1). In summary, this provided a new treatment mode for the hot-drawing of fibers.