Influence of processing on structure of beta-nucleated poly(propylene) fibers

摘要

Fibers colored with quinacridone pigment spun at low take-up velocities were obtained. The spun fibers, with a very high beta-form content, were drawn at room temperature and at a temperature of 120degreesC at different draw ratios. They were then heat stabilized at different temperatures, ranging from 140 to 150degreesC for different time intervals. As a result of drawing, the transition from beta to mesophase, as well as that from 9 to a, was observed. The beta to mesophase transition results from cold drawing at room temperature, while the beta to a transition results from drawing at 120degreesC. In both cases, the significant decrease of beta-form content occurs at the low draw ratio of 2. At higher draw ratios, the beta-form content gradually decreases, and at a draw ratio of 7 the beta-form disappears altogether. As a result of heat stabilization, the beta to a transformation was observed. The first change of the beta-form content was noticed at 140degreesC. For fibers stabilized at temperatures above 140degreesC, the decrease of the beta-form content is more significant and increases with the increase of the stabilization temperature. At 150degreesC, a rapid drop of the beta-form content occurs after only 3 min, and after a few more minutes the beta-form disappears. (C) 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1413-1418, 2004. [References: 59]