氢气/环己烷分离用聚酰胺膜的制备

Preparation of polyamide membrane for H _(2)/cyclohexane separation

膜材料性能是膜分离技术工业化应用的关键。首先,以2,6,14三氨基三蝶烯和4,4苯甲酰氯为合成单体,通过直接缩合酰化反应,制备了网状三蝶烯基聚酰胺聚合物。然后,并以溶液涂覆法,制备了截留型微孔聚酰胺膜。采用膜法气体分离方法,研究氢气环己烷混合气体的筛分分离性能。采用傅里叶转换红外光谱仪(FT IR)、核磁氢谱(^(1)H NMR)、X线衍射(XRD)等表征手段证实了聚酰胺聚合物的合成。利用扫描电子显微镜(SEM)分析了复合膜表面完整性及厚度。最后考察了进料浓度、操作温度和流量等操作参数对复合膜筛分分离H_(2)/环己烷体系性能的影响规律。结果表明,高进料浓度及低操作温度可有效提高膜性能且由于聚合物膜网状结构的存在,分离膜仅需15 kPa的跨膜压差(跨膜驱动力),即可实现99%以上的截留率。网状三蝶烯基聚酰胺聚合物膜在氢气净化方面具有较好的应用前景。

The properties of membrane materials are the key to the industrial application of membrane separation technology.Firstly,a reticulated tripterenyl polyamide polymer was prepared by direct condensation acylation with 2,6,14-triamino-tripterene and 4,4-benzoyl chloride as synthetic monomers.And the intercepting microporous polyamide film was prepared by solution coating.Then,the molecular sieving separation performance of hydrogen cyclohexane mixture was studied by a gas/vapor separation method.Finally,the successful synthesis of polyamide polymer was confirmed by Fourier transform infrared spectroscopy(FT-IR),^(1)H nuclear magnetic resonance(1H NMR)and X-ray diffraction(XRD).And the surface morphology and thickness of the polyamide membrane were analyzed by scanning electron microscopy(SEM).Finally,effects of feed concentration,operating temperature and flow rate on the molecular sieving performance of H_(2)/cyclohexane system were studied.The results showed that high feed concentration and low operating temperature could effectively improve the membrane performance,and feed pressure of 15 kPa was used to provide the transmembrane driving force and achieved a rejection of more than 99%due to network structure in the polymer membrane.The network tripterenyl polyamide polymer membrane had a good prospect in hydrogen purification.