FIELD: chemistry.
SUBSTANCE: polymer contains repeating units of the following formulas I-III: formula I;
formula II; and
formula III, where formula I can be associated with formula II or III, but can not be associated with itself; formula II can be associated with formula I or III, but can not beassociated with itself; and formula III may be associated with formula I or II, or with itself, in which Ar1 is
; Ar2 is
; Ar1' is a divalent group derived from Ar1; Ar1" is a trivalent group derived from Ar1; X and Y are selected from O, S and N-phenyl. The method of producing the above polymer is that thermal treatment of the aromatic polyimide precursor containing a repeating unit of formula IV is carried out:
formula IV, in which Ar1 and Ar2 have the above meanings; o-FG is selected from the group consisting of -OH and -NH-phenyl. Thermal treatment is carried out by irreversible and intramolecular rearrangement at temperatures of 350°C to 500°C. From the above polymer, a membrane is obtained to separate the gases. The method of separating the liquid components consists in that the separation device comprising the above-mentioned separation membrane is first provided. In the separation device, the feed liquid is provided that contains a mixture of the first fluid and, at least, the second fluid. Then, a product is selected from the separation device, in which the first liquid has a higher purity than in the feed liquid.
EFFECT: invention allows to obtain a polymer with improved mechanical properties, which has an increased free volume and a narrower size distribution of the free volume structure, and to obtain a membrane with a high gas permeability.
9 cl, 5 dwg, 2 tbl, 5 ex
Authors
Dates
2017-10-03—Published
2013-08-02—Filed