UV-crosslinked poly(PEGMA-co-MMA-co-BPMA) membranes: Synthesis, characterization, and CO2/N2 and CO2/CO separation

A series of CO 2 -philic terpolymers were prepared by free radical polymerization using three monomers, poly(ethylene glycol) methyl ether methacrylate (PEGMA), methyl methacrylate (MMA), and 4-hydroxybenzophenone (BPMA), to develop CO 2 /N 2 and CO 2 /CO separation membranes. The terpolymers, poly(PEGMA-co-MMA-co-BPMA) (PMB), were cast into thin precursor films, which were then crosslinked by a UV-induced photochemical reaction between benzophenone and the alkyl group to produce crosslinked membranes (X-PMB). The gas permeabilities of the X-PMB membranes were influenced by the PEGMA content due to increased CO 2 solubility by the polar ether groups of PEGMA. As the content of PEGMA was increased from 60 to 90 wt%, the permeability of CO 2 increased from 49.7 to 110.7 barrer. The permeabilities of CO and N 2 also increased from 1.92 to 3.68 barrer and from 1.01 to 2.21 barrer, respectively. X-PMB9 with 90 wt% of PEGMA showed the best performance, where CO 2 permeability, CO 2 /N 2 selectivity, and CO 2 /CO selectivity were 110.7 barrer, 49.9, and 30.1, respectively. This membrane performance is comparable to or better than that of a commercially available membrane material, PEBAX, indicating that the X-PMB could be usefully applied to CO 2 separation membranes in carbon capture and utilization. • A series of crosslinked CO 2 -philic terpolymer membranes with PEG moiety were prepared. • The crosslinking reaction was carried out using benzophenone photochemistry. • The gas separation properties was controlled by the PEG content of terpolymer. • The crosslinked membranes showed excellent CO 2 /N 2 and CO 2 /CO separation properties.