A new series of six imidazolium-based ionenes containing aromatic amide linkages has been developed. These ionene-polyamides are all constitutional isomers varying in the regiochemistry of the amide linkages (para, meta) and xylyl linkages (ortho, meta, para) along the polymer backbone. The physical properties as well as the gas separation behaviors of the corresponding membranes have been extensively studied. These ionene-polyamide membranes show excellent thermal and mechanical stabilities, together with self-healing and shape memory characteristics. , terephthaloyl chloride; API, 1-(3-aminopropyl)imidazole; Xy, xylyl; Tf 2 N, bis(trifluoromethylsulfonyl) imide; IC, isophthaloyl chloride), where the amide and xylyl linkages are attached at para and meta positions, exhibit superior selectivity for CO 2 /CH 4 and CO 2 /N 2 gas pairs. We also demonstrate the transport properties and diverse applicability of our newly developed ionene-polyamides, particularly [TC-API(p)-Xy][Tf 2 N], for various industrial applications. Most importantly, [TC-API(p)-Xy][Tf 2 N] and [IC-API(m)-Xy][Tf 2 N] membranes (TC

1,2,3-Trimethoxypropane (1,2,3-TMP) is the trimethyl ether of propane-1,2,3-triol, better known as glycerol, which can be derived from triglycerides originating from either plant or animal sources. Despite its simple structure and the ubiquity of its glycerol precursor, successful synthesis of 1,2,3-TMP was only recently reported in the literature, with studies suggesting it may be a "green" and nontoxic alternative to solvents such as diglyme, a constitutional isomer. However, no thermophysical properties of 1,2,3-TMP have yet been reported. Furthermore, the structure of 1,2,3-TMP is also analogous to polyether solvents used in the Selexol process for removal of CO 2 and other "acid" gases from CH 4 , H 2 , etc. As such, examining the solubility of CO 2 in 1,2,3-TMP is also of interest. This work details our initial studies and characterization of 1,2,3-TMP as a physical solvent for CO 2 absorption, as well as the characterization of its density, viscosity, and vapor pressure with respect to temperature. 1,2,3-TMP exhibits favorable properties, and glycerol-derived triethers warrant deeper consideration as new solvents for CO 2 absorption and other gas treating applications.

A new family of six ionenes containing aromatic amide linkages has been synthesized from ready available starting materials at scales up to ∼50 g. These ionene-polyamides are all constitutional isomers and vary only in the regiochemistry of the amide linkages (para, meta) and xylyl linkages (ortho, meta, para) which are present in the polymer backbone. This paper details the synthesis of these ionenes and associated characterizations. Ionene-polyamides exhibit relatively low melting points (∼150 oC) allowing them to be readily processed into films and other objects. These ionene-polyamide materials are being developed for further study as polymer membranes for the separations of gases such as CO2, N2, CH4 and H2.

Here, we report the synthesis and thermophysical properties of seven primarily aromatic, imidazolium-based polyamide ionenes. The effects of varied para-, meta-, and ortho-connectivity, and spacing of ionic and amide functional groups, on structural and thermophysical properties were analyzed. Suitable, robust derivatives were cast into thin films, neat, or with stoichiometric equivalents of the ionic liquid (IL) 1-benzy-3-methylimidazolium bistriflimide ([Bnmim][Tf2N]), and the gas transport properties of these membranes were measured. Pure gas permeabilities and permselectivities for N2, CH4, and CO2 are reported. Consistent para-connectivity in the backbone was shown to yield the highest CO2 permeability and suitability for casting as a very thin, flexible film. Derivatives containing terephthalamide segments exhibited the highest CO2/CH4 and CO2/N2 selectivities, yet CO2 permeability decreased with further deviation from consistent para-linkages.

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