镧系金属有机骨架/聚酰亚胺复合材料的制备及其性能

采用水热法合成两种含镧系稀土金属的金属有机骨架：1，3，5-均苯三甲酸铽（Tb （BTC））和1，3，5-均苯三甲酸铕（Eu （BTC）），采用原位法以1，4-双（2-三氟甲基-4-氨基苯氧基）苯（6FAPB）和1，2，3，4-环丁烷四酸二酐（CBDA）为单体，将Tb （BTC）和Eu （BTC）分别引入到聚酰亚胺（PI）中，制备出Tb （BTC）和Eu （BTC）质量分数分别为7wt%的Tb （BTC）/PI和Eu （BTC）/PI两种复合材料膜。利用FTIR、紫外-可见光谱仪（UV-vis）、TGA、XRD、SEM、万能拉伸试验机和气体渗透性测试等对Tb （BTC）/PI和Eu （BTC）/PI复合材料的结构和性能进行表征。研究结果表明，Tb （BTC）和Eu （BTC）含有较少的孔结构，且孔径在介孔范围，但热稳定性较高。Tb （BTC）和Eu （BTC）的加入提高了Tb （BTC）/PI和Eu （BTC）/PI复合材料的热性能和力学性能，玻璃化转变温度由纯PI （6FAPB-CBDA）的351.9℃分别提高到358.0℃和354.8℃，失重5%热分解温度由431.6℃分别提高到447.8℃和441.1℃，拉伸强度由60.8 MPa分别提高到77.7 MPa和70.4 MPa，杨氏模量由1.54 GPa分别提高到2.80 GPa和2.17 GPa。但Tb （BTC）/PI和Eu （BTC）/PI复合材料膜的光透明性有所降低，500 nm处的光透过率由82.3%分别下降到23.0%和24.2%。气体渗透测试结果表明，Tb （BTC）和Eu （BTC）的加入均可提高PI （6FAPB-CBDA）膜的气体渗透性，Eu （TBC）/PI对H₂、O₂、N₂和CO₂的渗透性较高，分别为119.23、15.02、3.21和90.35 Barrer，O₂/N₂为4.68，CO₂/N₂为28.15。

Preparation and properties of lanthanide metal-organic frameworks/polyimide composites

Two kinds of lanthanide metal-organic frameworks such as terbium benzene-1,3,5-tricarboxylate (Tb(BTC)) and europium benzene-1,3,5-tricarboxylate (Eu(BTC)) were synthesized by hydrothermal method. 1,4-bis(2-trifluoromethyl-4-aminophenoxy)benzene (6FAPB) and 1,2,3,4-cyclobutane dianhydride (CBDA) as the monomers of polyimide (PI), the Tb(BTC)/PI and Eu(BTC)/PI composites containing 7wt% Tb(BTC) or Eu(BTC) (mass fraction) were prepared by the in-situ polymerization. The structure and properties of the Tb(BTC)/PI and Eu(BTC)/PI composites were characterized by FTIR, UV-visible spectrometer (UV-vis), TGA, XRD, SEM, universal tensile testing machine and gas permeabilities testing. These experimental results show that Tb(BTC) and Eu(BTC) contain very few pore structures, belonging to the mesoporous range, and exhibit high thermal stabilities. The introduction of Tb(BTC) and Eu(BTC) improves the thermal and mechanical properties of PI(6FAPB-CBDA). The glass transition temperatures increase from 351.9℃ of pure PI(6FAPB-CBDA) to 358.0℃ and 354.8℃, and the 5% thermal decomposition temperatures increase from 431.6℃ to 447.8℃ and 441.1℃. The tensile strengths of Tb(BTC)/PI and Eu(BTC)/PI composites increase from 60.8 MPa to 77.7 MPa and 70.4 MPa, and the Young's modulus increase from 1.54 GPa to 2.80 GPa and 2.17 GPa, respectively. However, the optical transmittances at 500 nm of Tb(BTC)/PI and Eu(BTC)/PI composites reduce from 82.3% to 23.0% and 24.2%. The results of gas permeability testing show that both of Tb(BTC) and Eu(BTC) can improve the gas permeabilities of the PI-(6FAPB-CBDA) membrane. The effect of Eu(BTC) is better than Tb(BTC). The permeabilities of H₂, O₂, N₂ and CO₂ of Eu(TBC)/PI composite are 119.23, 15.02, 3.21 and 90.35 Barrer, respectively, and O₂/N₂ is 4.68, CO₂/N₂ is 28.15.