To develop membrane materials for gas separation, a series of semi-alicyclic polyimides was synthesized using one-step thermal solution imidization from an alicyclic dianhydride with non-planar twisted structure, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA). All synthesized polyimides exhibited amorphous structures and superior thermal stability, with high glass transition temperatures (242–288 °C) withstanding high operation temperature and pressure. They also showed excellent solubility in many polar organic solvents commonly used in the fabrication of gas separation membranes. The gas permeation properties of the polyimide membranes were measured for six representative gases (H2, CO2, O2, CO, N2, and CH4). The gas permeabilities and selectivities of polyimide membranes were significantly influenced by the chemical structure of the diamines, which could be explained reasonably by the kinetic diameter of gases, the fractional free volumes, and d-spacing values of the polyimides. Two DOCDA-based polyimides showed very high selectivities for H2/CH4 and CO2/CH4 and slightly low permeabilities for H2 and CO2, which performances were comparable to the commercial polyimide materials such as P84® and Matrimid® used in gas separation field.
Bibliographical noteFunding Information:
This research was supported by the performed as a project No. KK1601-F00 (Membrane Technology for Production of High-Purity Carbon Resources from By-product Gases) and supported by the Korea Research Institute of Chemical Technology . This work was also supported by “Next Generation Carbon Upcycling Project” (Project No. 2017M1A2A2042517 ) through the National Research Foundation funded by the Ministry of Science and ICT, Republic of Korea .
© 2018 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry