Amine-Functionalized Flat Sheet Porous Polymer Sorbents with Oxidative Degradation Resistance for Gas Capture Applications

Amine-functionalized sorbents are highly effective for their ability to efficiently adsorb low-concentration carbon dioxide (CO 2 ). However, when these sorbents are exposed to heat, oxygen, and other atmospheric conditions, they can undergo oxidative degradation, decreasing the ability of these sorbents to adsorb CO 2 . Here, we study the degradation of an amidoxime-modified polymer of intrinsic porosity (PIM-1-AO) that has been cast on a flat sheet and functionalized with either tris(3-aminopropyl)amine (TAPA) or tris(3-aminoethyl)amine (TAEA) yielding MC-PIM-1-AO-TAPA or MC-PIM-1-AO-TAEA, respectively. The sorbents were subjected to accelerated degradation under humid air at 75 °C for up to 5 days. We demonstrated that MC-PIM-1-AO-TAPA not only exhibits superior resistance to degradation compared to MC-PIM-1-AO-TAEA but also outperforms any other amine-functionalized sorbents aged under similar conditions, suggesting that propyl chains add increased stability to the amine compared to ethyl chains.