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

Abstract

In this article, the supercritical carbon dioxide (Sc-CO2) 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 g·d-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-CO2 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-CO2. 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 g·d-1. In summary, this provided a new treatment mode for the hot-drawing of fibers.