【作者】 张莉莉；

【导师】 王志；

【作者基本信息】 天津大学 ， 化学工程， 2004， 硕士

【摘要】 分离CO2的固定载体膜同时具备良好的稳定性和渗透选择性能，是一类很有发展前景的新型分离膜。聚合物共混改性是开发具有崭新性能膜材料的重要途径。 本文利用我们实验室已开发出的固定载体膜材料—聚N-乙烯基-γ-氨基丁酸钠(PVSA)和聚乙烯基胺（PVAm）研制出PVSA/PVAm共混膜材料，并以聚醚砜(PES)超滤膜为支撑体制成共混复合膜。采用现代分析测试手段红外、X射线衍射（XRD）、材料拉伸测试及环境扫描电子显微镜（ESEM）对PVSA和共混聚合物的微观结构、共混聚合物的拉伸性能和共混复合膜的形貌特征进行了研究。结果表明，通过聚合物共混的方法，膜材料的力学性能得到了改善；两种聚合物相容性良好，电镜显示共混复合膜表层致密光滑，与支撑层紧密结合。以CO2/CH4体系为研究对象，考察了共混复合膜的透过选择性能，系统研究了各种因素如耦合效应、PVSA/PVAm配比、铸膜环境温度及湿度对膜结构和性能的影响。以CO2、CH4、N2、O2为研究对象，系统地探讨了该共混复合膜对不同气体体系的分离性能。研究结果表明，以该共混聚合物为表层，PES超滤膜为支撑层制得的PVSA/PVAm共混复合膜综合性能优越。在PVSA wt%＝33.3%，压力为 1.04atm时，PVSA/PVAm共混复合膜的CO2渗透速率和CO2/CH4理想分离因子分别为6.48×10-6 cm3 (STP)cm-2 s-1 cmHg-1和 217。用 50%CO2和 50%CH4组成的混合气进行测试时，在CO2分压为 0.518atm的情况下，CO2的渗透速率达到了 5.56×10-6cm3(STP) cm-2 s-1 cmHg-1，CO2/CH4的分离因子为 49.7。不同气体通过该共混复合膜的快慢顺序为CO2＞O2＞CH4＞N2，理想分离因子大小为αCO2/N2＞αCO2/CH4＞αCO2/O2。 本论文还采用丙烯酰胺与马来酸酐进行共聚并水解得到聚合物马来酸钠－丙稀酰胺（MAS-Am），采用该共聚物为表层，PES超滤膜为支撑层制得复合膜，初步探讨了该复合膜对CO2/CH4体系的渗透选择性。结果表明，相对PVSA/PVAm共混复合膜而言，该膜的CO2渗透速率以及CO2/CH4的分离因子较低。在纯气测试中，当压力为 1.04atm时，该复合膜CO2的渗透速率为 1.04×10－6 cm3(STP) cm-2s-1 cmHg-1，CO2/CH4理想分离因子为 66。当用 50%CO2和 50%CH4组成的混合气进行测试时，CO2分压为 0.56atm时，CO2渗透速率为 5.58×10－7 cm3(STP) cm-2 s-1cmHg-1，CO2/CH4分离因子为 43.6。更多还原

【Abstract】 Fixed carrier membranes for CO2 separation are promising membranes, whichhave the advantages of both stability and good permselectivity. Polymer blending is auseful method which can result in a new product with properties not found in singlepolymers. Poly(N-vinyl-γ-sodium aminobutyrate)(PVSA) and polyvinyamine(PVAm)are two fixed carrier membrane materials developed by our research group. In thiswork, fixed carrier blend materials—PVSA/PVAm were prepared by using PVSA andPVAm successfully. Composite membranes were developed with the blend materialPVSA/PVAm as active layers and polyethersulfone ultrafiltration membrane assupport. Tensile elongation measurement was used to test the mechanics of blendmaterials. FTIR(Fourier Transform Infrared Spectroscopy), XRD(X-ray diffractions)and ESEM (Environmental Scanning Electron Microscope) were employed tocharacterize the structure of PVSA and blend materials PVSA/PVAm and themorphology of the PVSA/PVAm blend composite membranes. The results show thatthe mechanical properties of the blend polymer are better than that of the two singlepolymers, the active layers of the composite membranes are smooth and dense. The permselectivities of the blend composite membranes were measured withpure CO2 and CH4 gas as well as binary mixture of CO2 and CH4. The effects of manykinds of factors such as “coupling effects”, PVSA/PVAm ratio, cross-linking andcasting temperature and relative humidity on performances of the PVSA/PVAm blendcomposite membranes were discussed in detail. The permselectivity of the blendmembranes for CO2/N2 and CO2/O2 were also measured. The PVSA/PVAm blendcomposite membranes present excellent comprehensive performances, which arebetter than single PVSA and PVAm composite membranes. For pure feed gases, atpressure of 1.04 atm，PVSA wt%=33.3%, the PVSA/PVAm blend compositemembrane displays a CO2 permeation rate of 6.48×10-6 cm3 (STP)cm-2 s-1 cmHg-1 andCO2/CH4 ideal separation factor of 217. For mixed feed gas composed of 50% CO2and 50% CH4, at CO2 partial pressure of 0.518 atm，PVSA wt%=33.3%, thePVSA/PVAm blend composite membrane displays a CO2 permeation rate of5.56×10-6 cm3 (STP)cm-2 s-1 cmHg-1 and CO2/CH4 ideal separation factor of 49.7. Thepermeation rate sequence of different gases is CO2＞O2＞CH4＞N2, and the idealselectivity sequence of different gas systems is α CO2/N2＞αCO2/CH4＞αCO2/O2. II<WP=4>Copolymer poly( maleic acid sodium-co-acrylamide) (MAS-Am) wassynthesized by using maleic anhydride and acrylamide. The composite membraneMAS-Am/PES were developed with this material as active layer and polyethersulfoneultrafiltration membrane as support. And the permselectivities of the compositemembrane were also measured with pure CO2 and CH4 gas as well as binary mixtureof CO2 and CH4. For pure feed gases, at pressure of 1.04 atm，MAS-Am compositemembrane displays a CO2 permeation rate of 1.05×10-6 cm3 (STP)cm-2 s-1 cmHg-1 andCO2/CH4 ideal separation factor of 66. For mixed feed gas composed of 50% CO2 and50% CH4, at CO2 partial pressure of 0.56 atm, the MAS-Am composite membranedisplays a CO2 permeation rate of 5.58×10-7 cm3 (STP)cm-2 s-1 cmHg-1 and CO2/CH4ideal separation factor of 43.6.更多还原