聚四氟乙烯短纤维的热及化学稳定性研究

Study on thermal and chemical stability of PTFE staple fiber

通过表观形态观测,得出聚四氟乙烯(PTFE)短纤维的直径服从高斯分布。针对细度差异性较大的PTFE短纤维,提出一种基于线密度差异性的单根纤维追踪测量法,用于测试酸碱处理前后纤维的力学性能。结果表明,经常温酸碱处理后,纤维断裂强度基本无变化,而初始模量减小,断裂伸长率增大;高温酸碱处理后的纤维断裂强度略有增大而断裂伸长率减小;经干热空气和沸水处理后,纤维的断裂强度基本无变化,而断裂伸长率由于解取向略有降低。此外,热失重分析表明PTFE短纤维具有优异的耐高温性能。

The diameter and Gauss distribution of PTFE staple fiber were obtained by observing the longitudinal morphology of the fiber. For the great CV value of PTFE staple fiber, a tracking measurement method based on different line density of single fiber was proposed to test mechanical properties of fibers before and after treatment. After treated by acid and alkali under normal temperature, the breaking tenacity of fiber was almost unchanged, while the tensile modulus decreased and the elongation at break increased. The breaking tenacity of fiber slightly increased and the elongation at break decreased after treating by acid and alkali under high temperature. After treating by hot air and boiling water,the breaking tenacity of fiber varied little and the elongation at break slightly decreased due to disorientation. In addition, TG analysis showed that PTFE staple fiber had excellent high temperature resistance.