Analysis of microporous membranes obtained from polypropylene films by stretching
Analysis of microporous membranes obtained from polypropylene films by stretching
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DOI：
10.1016/j.memsci.2007.01.023
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发表时间：
2007-04-05
影响因子：
9.5
通讯作者：
Carreau, Pierre J.
中科院分区：
文献类型：
--
作者：
Sadeghi, Farhad;Ajji, Abdellah;Carreau, Pierre J.
选用5种不同的聚丙烯树脂，通过熔融挤出和拉伸（流延膜工艺）制备微孔膜。研究了聚合物熔体延伸性能对成核层状结晶的影响。通过广角X射线衍射（WAXD）和傅里叶变换红外光谱（FTIR）方法研究了晶相和非晶相的排列和取向。适当调整挤出和冷却参数，得到具有合适形貌的均匀前驱体膜。随后采用退火、冷拉伸和热拉伸来产生和扩大孔隙。结果表明，分子量是控制膜结构的最重要的物质因素。还研究了退火和拉伸参数的作用。测量对水蒸气（在大气条件下）和氮气（在压力下）的渗透性。实验结果表明，渗透率随压力的增加而增加，并经历了从努森扩散到波依维耶流动的转变。(c)2007 Elsevier B.V.保留所有权利。
Five different polypropylene resins were selected to develop microporous membranes through melt extrusion and stretching (cast film process). The effect of the polymer melt elongation properties on the row-nucleated lamellar crystallization was investigated. The arrangement and orientation of the crystalline and amorphous phases were examined by WAXD (wide angle X-ray diffraction) and FTIR (Fourier transform infrared) methods. The extrusion and cooling parameters were adjusted properly to obtain uniform precursor films with appropriate morphology. Annealing, cold and hot stretching were consequently employed to generate and enlarge the pores. It was found that molecular weight was the most important material factor that controlled the membrane structure. The role of annealing and stretching parameters was also investigated. The permeability to water vapor (under atmospheric condition) and nitrogen (under pressure) was measured. It was observed that the permeability increased with increasing pressure and went through a transition from Knudsen diffusion to Poiseuille flow. (c) 2007 Elsevier B.V. All rights reserved.