Microporous formation and evolution mechanism of PTFE fibers/isotactic polypropylene membranes by interface separation
Microporous formation and evolution mechanism of PTFE fibers/isotactic polypropylene membranes by interface separation
复制标题
界面分离PTFE纤维/等规聚丙烯膜微孔形成及演化机制
DOI：
10.1016/j.memsci.2021.119333
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发表时间：
2021-04-22
影响因子：
9.5
通讯作者：
Guo, Shaoyun
中科院分区：
文献类型：
--
作者：
Fang, Wenxiang;Liang, Guixue;Guo, Shaoyun
研究微孔的形成和演化机理对制备高性能微孔膜起着至关重要的作用。基于聚四氟乙烯纤维与PP基体在连续双向拉伸过程中的界面分离，提出了一种不同于以往报道的PP微孔膜的形成机理。实验结果表明，由微纤化PP填充的初始微裂纹起源于垂直于纵向拉伸方向的PTFE纤维-PP基体界面。随着应变的增加，微纤化的PP进一步拉伸，最终以相对较低的应变(200%)形成微纤化的PP膜。随后的横向拉伸导致原纤化PP的分离，形成了良好的微孔结构。结果表明，双向拉伸后的PTFE/PP膜比β-PP膜具有更窄的孔径分布、更高的孔隙率、更高的氮气通量和更高的纯水通量。
Studying microporous formation and evolution mechanism plays a crucial role in fabricating high-performance microporous membranes. A formation mechanism of PP microporous membranes, different from those reported previously, was proposed based on the interface separation of PTFE fibers and PP matrix during sequential biaxial stretching. The experimental results indicated that the initial microcracks, which were filled by microfibrillated PP, were originated from PTFE fibers-PP matrix interfaces perpendicular to the longitudinal stretching direction. As the strain increased, microfibrillated PP was further elongated, ultimately forming microfibrillated PP membranes at a relatively low strain (200%). The subsequent transverse stretching caused the separation of fibrillated PP to form an excellent microporous structure. As a result, PTFE/PP membranes after biaxial stretching exhibited the narrower pore size distribution, higher porosity, higher N2 flux and pure water flux than beta-PP membranes.