本文以聚丙烯腈(PAN)为前驱体，N-甲基吡咯烷酮为溶剂，水为凝胶介质，采用干-湿相转化法制备不对称PAN基聚合物膜，通过FT-IR、XRD、SEM等手段进行结构表征及恒压力变体积法测试气体渗透性能，主要探讨了PAN膜在空气预氧化处理过程中的化学和微结构变化规律及预氧化工艺条件（预氧化温度、恒温时间及空气流率）对PAN膜的结构和气体渗透分离性能的影响。研究表明，在空气预氧化过程中，PAN膜的化学结构经氧化交联由线性结构转变为体型结构，PAN由热塑性变为热固性材料。预氧化工艺对PAN膜性能有很大的影响。提高预氧化温度、延长恒温时间以及增大空气流率均有利于膜性能的提高，但当预氧化条件超过一定程度后，膜性能反而降低。SEM分析表明预氧化处理后的膜仍具有聚合物膜的基本孔形貌

The asymmetric membranes were prepared by dry-wet phase inversion method, in which polyacrylonitrile (PAN) was used as the precursor, N-methylpyrrolidone as the solvent and water as the coagulant. The change of chemical and microstructure during the air preoxidation and effect of preoxidation conditions on the structure and gas separation performance of obtained PAN membranes were investigated via FT-IR, XRD, SEM and constant pressure variable volume method. Results indicate that the chemical structure of PAN membrane is transformed from linear structure into three-dimensional structure due to oxidative crosslinking reaction during the preoxidation process which makes PAN membranes turn into thermosetting materials from thermoplastic ones. Peoxidation process also greatly influences the gas separation performance of PAN membranes. Increasing the preoxidation temperature, holding time and air flow rate are all beneficial to improve the performance. However, the excessive preoxidation makes the performance decrease. SEM shows that the preoxidation membrane has the basic pore morphology of polymer membrane.

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