Polyimide gas separation membranes
AssigneeE. I. Du Pont de Nemours and Company
InventorRichard A. Hayes
Life of this patent
Estimating the term…
Abstract
A highly permeable aromatic polyimide gas separation membrane and the process of using it are disclosed. The aromatic polyimide has the formula ##STR1## wherein --Ar-- is ##STR2## or mixtures thereof, --X, --X.sub.1, --X.sub.2 and --X.sub.3 independently are alkyl groups having 1 to 6 carbon atoms or aromatic groups having 6 to 13 carbon atoms, and --Z is --H, --X, --X.sub.1, --X.sub.2, or --X.sub.3 ; and R is ##STR3## or mixtures thereof.
Claims6
A gas separation membrane formed of an aromatic polyimide of the formula ##STR7## where --Ar-- is ##STR8## or mixture thereof, and R is ##STR9## or mixtures thereof and --X, --X.sub.1, --X.sub.2, and --X.sub.3 are independently alkyl groups having 1 to 6 carbon atoms or aromatic groups having 6 to 13 carbon atoms, and --Z is --H, --X, --X.sub.1, --X.sub.2, or --X.sub.3.
A process of separating two or more gases comprising of steps of bringing a mixture of two or more gases into contact with one side of a permselective membrane which is formed from an aromatic polyimide of the formula ##STR11## where --Ar-- is ##STR12## or or mixtures thereof, and R' is ##STR13## or mixtures thereof and --X, --X.sub.1, --X.sub.2, and --X.sub.3 are independently alkyl groups of 1 to 6 carbon atoms, or aromatic group having 6 to 13 carbon atoms and --Z is --H, --X, --X.sub.1, --X.sub.2, or --X.sub.3 whereby one of said gases permeates said membrane at a different productivity rate than at least one other gas.
Dependencies are inferred from the claim text.