# US 2014/0360366 A1 · Azide crosslinked and physically crosslinked polymers for membrane separation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360366 A1 - Document ID: US20140360366A1 - Status: Published application - Kind: A1 - Application number: 14/345,343 - Filed: 2012-09-20 - Published: 2014-12-11 - Earliest claimed: 2011-09-21 - Assignees: Dow Global Technologies LLC - Applicants: Dow Global Technologies - Inventors: Scott T. Matteucci; Clark H. Cummins; William J. Kruper; Harry Craig Silvis - Web page: https://patentgrep.com/patent/US20140360366A1 ## CPC - B01D 71/58: Other polymers having nitrogen in the main chain, with or without oxygen or carbon only - B01D 53/22: by diffusion (manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00) - C08K 5/28: Azides - C08K 5/43: Compounds containing sulfur bound to nitrogen - B01D 2053/221: {Devices} - B01D 2257/504: Carbon dioxide - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract The present invention appreciates that compounds comprising ester linkages and nitrogen-containing moieties that are at least divalent (e.g., urea, urethane, amide, etc.) can be crosslinked with azides to form membranes that are resistant to C02 plasticization, that are selective for acid gases relative to nonpolar gases such as hydrocarbons, and that have high acid gas flux characteristics. The resultant membranes have stable structure and stable separation properties at higher temperatures and pressures. The membranes are compatible with many industrial processes in which polar gases are separated from nopolar gases. In an exemplary mode of practice, the membranes can be used to separate acid gases from the hydrocarbon gases in natural or non-acid gas components of flue gas mixtures (e.g., N2, O2, etc.). ## Claims ### Claim 1 A physically and chemically cured membrane composition comprising an inlet face and an outlet face, and incorporating ingredients comprising: a) at least one membrane compound comprising a plurality of ester moieties and a plurality of N-containing backbone moieties, wherein each N-containing moiety is at least divalent, wherein the at least one compound comprises ester repeat units of Formula I: and at least one second repeat unit selected from the esteramide units of Formula II and/or the esteramide units of Formula III, and optionally at least one repeat unit of the ester-urethane units of Formula IV: wherein: each R is independently selected from a C2-C20 non-aromatic hydrocarbylene group, a C2-C20 non-aromatic heterohydrocarbylene group, or a polyalkylene oxide group having a group molecular weight of from about 100 to about 5000 g/mol; each R1 independently is a bond or a C1-C20 non-aromatic hydrocarbylene group; each R2 independently a C1-C20 non-aromatic hydrocarbylene group; each RN independently is —N(R3)—Ra—N(R3)—, where each R3 is independently H or a C1-C6 alkyl or RN is a C2-C20 heterocycloalkylene group containing at least two nitrogen atoms; w+x+y+z=1, 0