Polyimide gas separation membranes
AssigneeE. I. Du Pont de Nemours and Company
InventorRichard A. Hayes
Life of this patent
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Abstract
Aromatic polyimide gas separation membranes containing the repeating unit: ##STR1## where --Ar-- =is ##STR2## or mixtures thereof, ##STR3## or mixtures thereof Where --X, X.sub.1, X.sub.2, and X.sub.3 are independently primary or secondary alkyl groups having 1 to 6 carbon atoms preferably methyl or ethyl, --Z is --H, --X, --X.sub.1, --X.sub.2, or --X.sub.3 and R' is ##STR4## where n=0 to 4 or alkylene radicals of 1 to 3 carbon atoms and --R"-- is ##STR5##
Claims8
A process for separating one or more gases from a mixture of two or more gases comprising bringing said mixture of two or more gases under pressure into contact with one side of an aromatic gas separation membrane consisting essentially of repeating linear units of the formula:
- ##STR11## where --Ar-- is ##STR12## or mixtures thereof, ##STR13## or mixtures thereof, where --X, --X.sub.1, --X.sub.2, and --X.sub.3 are independently primary or secondary alkyl groups having 1 to 6 carbon atoms, --Z is --H, --X, --X.sub.1, --X.sub.2, or --X.sub.3 and R' is ##STR14## or alkylene groups of 1 to 3 carbon atoms, and --R"-- is ##STR15##
An aromatic polyimide gas separation membrane consisting essentially of repeating linear units of the formula ##STR19## where --Ar-- is ##STR20## or mixtures thereof, ##STR21## or mixtures thereof, where --X, X.sub.1, X.sub.2, and X.sub.3 are independently primary or secondary alkyl groups having 1 to 6 carbon atoms, --Z is --H, --X, --X.sub.1, --X.sub.2, or --X.sub.3 and R' is ##STR22## or alkylene radicals of 1 to 3 carbon atoms and where n=0 to 4, --R"-- is ##STR23##
Dependencies are inferred from the claim text.