Ending Aging in Super Glassy Polymer Membranes

Abstract

Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4‐methyl‐2‐pentyne) (PMP), and polymers with intrinsic microporosity (PIM‐1) reduces gas permeabilities and limits their application as gas‐separation membranes. While super glassy polymers are initially very porous, and ultra‐permeable, they quickly pack into a denser phase becoming less porous and permeable. This age‐old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.

Side-chain engineering of ladder-structured polysilsesquioxane membranes for gas separations

“…S6) [16]. As such, the solid-state NMR was utilized as an alternative option, since the measurement of the T 1 times as described elsewhere [41][42][43] allows for the analysis of chain dynamics in LPSQ membranes. These recent studies have been proved extremely useful in examining chain mobility of polymers through the examination of the relative T 1 time change in analogous assigned carbons, as the degree of increase in T 1 time is representative of lower chain mobility.…”

Trends and challenges for microporous polymers

“…One way to stabilize the polymer matrix is by introducing several different kinds of fillers to design mixed matrix membranes (MMMs). Main examples for fillers that are used for MMMs are porous materials like MOFs, [101][102][103] carbon nitrides 104 but also microporous polymer networks [105][106][107] and related molecular fillers like organic cages (Fig. 6).…”

Origins and Evolution of Inorganic-Based and MOF-Based Mixed-Matrix Membranes for Gas Separations

“…(a) (b) Another important development in 2014 was the suppression of aging in MMMs that was reported in the work of C. H. Lau, et al [243]. In this work, three highly permeable super glassy polymers (PTMSP, PMP, and PIM-1) and their PAF-1 MMMs were tested for CO 2 permeation over a period of 240 days.…”