Xylylene based polyether membranes for gas separation

A process of separating gases comprising:

• A. contacting one side of a semi-permeable gas separation membrane with a feed gas mixture under pressure, wherein the membrane divides a separation chamber into a high pressure side into which the feed gas mixture is fed and a low pressure side;
• B. maintaining a pressure differential across the membrane under conditions such that at least one gaseous component in the feed gas mixture selectively permeates through the membrane from the high pressure side to the low pressure side of the membrane;
• C. removing from the low pressure side of the membrane permeated gas which is enriched in at least one selectively permeating gaseous component;
• and
• D. removing from the high pressure side of the membrane non-permeated gas which is depleted in at least one selectively permeating gaseous component;
• wherein the membrane comprises a thin discriminating region of a xylylene based polyether polymer possessing a backbone structure corresponding to the formula:
• ##STR6## wherein R is individually in each occurrence a hydrogen radical, a monovalent C.sub.1-12 hydrocarbyl radical, a C.sub.1-12 halohydrocarbyl radical, and a halogen,
• Ar.sub.1, Ar.sub.2, Ar.sub.3, and Ar.sub.4 are individually in each occurrence a divalent aromatic residue selected from the group consisting of:
• A. an unsubstituted or inertly substituted phenylene, or an unsubstituted or inertly substituted naphthylene;
• B. a bisphenylene of the formula:
• ##STR7## wherein L is individually in each occurrence selected from the group consisting of a direct bond, a divalent C.sub.1-15 hydrocarbyl radical, a divalent C.sub.1-8 halohydrocarbyl radical, --O--, --CO--, --S--, --SO.sub.2 --, and --SS--,
• X is individually in each occurrence selected from the group consisting of a hydrogen radical, a monovalent C.sub.1-4 hydrocarbyl radical,
• a C.sub.1-4 halohydrocarbyl radical, and a halogen, and
• m is individually in each occurrence a positive integer between 1 and 4 inclusive;
• and
• C. a divalent bisphenyl fluorenyl or spiro indanyl radical;
• w is a positive integer between 0 and 3 inclusive;
• x is a positive integer between 1 and about 500 inclusive,
• y is a positive integer between 0 and about 500 inclusive, and
• z is a positive integer between 0 and about 500 inclusive, wherein the ratio of ##EQU15## is between about 0.002 and 1 inclusive;
• and n is a positive integer representing a degree of polymerization which provides a number-average molecular weight of at least about 3,000.