3899309 is referenced by 90 patents and cites 4 patents.

Gas separation membranes are made from aromatic polyimides, polyesters and polyamides in which the repeating unit of the main polymer chainA. has at least one rigid divalent subunit, the two main chain single bonds extending from which are not colinear,B. is sterically unable to rotate 360.degree. around at least one of these bonds, andC. has 50% or more of its main chain atoms as members of aromatic rings.

Title
Aromatic polyimide, polyester and polyamide separation membranes
Application Number
05/322,800
Publication Number
3899309
Application Date
January 11, 1973
Publication Date
August 12, 1975
Inventor
Richter John W
Hoehn Harvey Herbert
Assignee
E I du Pont de Nemours & Co
IPC
B01d 31/00
B01d 53/22
C08G 73/10
C08G 73/00
C08G 69/32
C08G 69/00
C08G 63/682
C08G 63/00
B01D 71/64
B01D 71/56
B01D 67/00
B01D 71/48
B01D 71/00
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