Polyimide gas separation membranes and process of using same
AssigneesE. I. Du Pont de Nemours and Company, L'Air Liquide
InventorRichard A. Hayes
Life of this patent
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Abstract
Novel aromatic polyimide gas separation membranes and the process of using such membranes to separate one or more gases from a gaseous mixture is disclosed. The polyimides are derived from a variety of aromatic tetracarboxylic dianhydrides used to form aromatic polyimide gas separation membranes and diamines of the formula ##STR1## where --X-- is a divalent radical such as --O-- or ##STR2## and --Ar'-- is a divalent radical such as phenylene, napthalene, biphenyl or ##STR3##
Claims12
A process for separating one or more gases from a gaseous mixture consisting essentially of bringing said gaseous mixture into contact with one side of a gas separation membrane whereby one or more of the gases permeates said membrane preferentially, said membrane being formed from an aromatic polyimide containing repreating units of the formula:
- ##STR21## or mixtures thereof, --Y is independently --H, alkyl groups having 1 to 6 carbon atoms, aromatic groups having 6 to 12 carbon atoms, or a halogen provided that at least one Y cannot be --H, where n is an integer from 1 to 4 and --R'-- is ##STR22## or mixtures thereof, where m is an integer from 0-4, said aromatic polyimide being of a film forming molecular weight.
A gas separation membrane for preferentially separating one or more gases from a gaseous mixture formed from an aromatic polyimide consisting essentially of repeating units of the formula:
- ##STR27## or mixtures thereof, --Y is independently --H, alkyl groups having 1 to 6 carbon atoms, aromatic groups having 6 to 12 carbon atoms, or halogen, provided that at least one --Y cannot be --H, where n is an integer from 1 to 4 and --R'-- is ##STR28## or mixtures thereof, where m is an integer from 0-4, said aromatic polyimide being of a film forming molecular weight.
Dependencies are inferred from the claim text.