Novel multicomponent fluid separation membranes
AssigneeE. I. Du Pont de Nemours and Company
InventorsOkan M. Ekiner, Richard A. Hayes, Phillip Manos
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Abstract
A process for preparing multicomponent gas separation membranes is disclosed. The process involves casting two or more solutions of polymer, and partially removing solvent from the side of the cast polymer that is to form the gas separation layer of the membrane. The membrane is then quenched to freeze its structure and then the remainder of the solvent removed to form the gas separation membrane.
Claims78
A multicomponent membrane comprising,
- a porous polymeric substrate and a polyamide separating layer for separating gases, wherein said polyamide has the formula ##STR28## where R is one of either ##STR29## or mixtures thereof where Z', Z", and Z"' are independently a carbon-carbon single bond, ##STR30## or mixtures thereof, Ar is ##STR31## where Z is a carbon-carbon single bond, ##STR32## or mixtures thereof, n is an integer such that the polymer is of film-forming molecular weight, --X, --X.sub.1, --X.sub.2 and --X.sub.3 are independently hydrogen, alkyl groups of 1 to 6 carbon atoms, alkoxy groups of 1 to 5 carbon atoms, phenyl or phenoxy groups, and --Y, --Y.sub.1, --Y.sub.2, --Y.sub.3, --Y.sub.4, --Y.sub.5, --Y.sub.6, --Y.sub.7, --Y.sub.8, --Y.sub.9, --Y10, --Y11, --Y.sub.12, --Y.sub.13, --Y.sub.14, --Y.sub.15 independently are X, X.sub.1, X.sub.2, X.sub.3, halogen, or alkyl groups of 1 to 6 carbon atoms.
A multicomponent membrane comprising a porous polymeric substrate and a polyimide separating layer for separating gases wherein said polyimide is an aromatic polyimide comprising repeating units of the formula:
- ##STR50## wherein R and R' are selected from the group ##STR51## where --Z-- is a carbon-carbon single bond, ##STR52## alkylene groups of 1 to 5 carbon atoms, --Ar-- is ##STR53## for mixtures thereof where Z', Z", Z"' independently are a carbon-carbon single bond, ##STR54## or alkylene groups of 1 to 5 carbon atoms, X, X.sub.1, X.sub.2 and X.sub.3 are independently, hydrogen, alkyl groups of 1 to 5 carbon atoms, alkoxy groups of 1 to 5 carbon atoms, phenyl or groups, --Y, --Y.sub.1, --Y.sub.2, --Y.sub.3, --Y.sub.4, --Y.sub.5, --Y.sub.6, --Y.sub.7, --Y.sub.8, --Y.sub.9, --Y.sub.10, --Y.sub.11, --Y.sub.12, --Y.sub.13, --Y.sub.14, and --Y.sub.15 independently are --X, --X.sub.1, --X.sub.2, --X.sub.3 or halogen, --Ar'-- is ##STR55## or mixtures thereof where Z' has the above-defined meaning, m is 0 to 100 mole percent, n is 0 to 100 mole percent, and (m+n)=100%.
A process for manufacture of a multicomponent gas separation membrane, comprising providing a solution of a film forming polymer as a first supporting layer, said film forming polymer of said solution being selected from the group of polysulfones, polyether sulfones, polyetherimides, polyimides, polyamide, copolymers thereof, and blends thereof, applying to a surface of said first supporting layer a second solution of a film forming polymer to provide a separating layer to form a nascent membrane of at least two layers, said film forming polymer of said second solution being selected from the group of polyetherimide, polyimide, polyamide, polyesters, polycarbonates, copolycarbonate esters, polyphenylene oxides, polyamideimides, cellulose acetates, ethyl cellulose and mixtures thereof, coagulating said nascent membrane, and drying said nascent membrane to form a multicomponent gas separation membrane.
Dependencies are inferred from the claim text.