Thermally rearranged polymer gas separation membrane having fluorinated cross-linked structure, and preparation method therefor

A polymer gas separation membrane, having a repeat unit represented by <Chemical Formula 1> or <Chemical Formula 2>, wherein the membrane is formed into a fluorine deposition layer, a transition layer and a thermally rearranged polymer base layer as fluorine atoms are distributed to have a concentration gradient from the surface:

• wherein
• Ar is an aromatic ring group selected from a substituted or unsubstituted tetravalent C6-C24 arylene group and a substituted or unsubstituted tetravalent C4-C24 heterocyclic group, wherein the aromatic ring group exists independently, two or more of them form a condensed ring or two or more of them are linked by a single bond, O, S, CO, SO2, Si(CH3)2, (CH2)p (1≤p≤10), (CF2)q (1≤q≤10), C(CH3)2, C(CF3)2 or CO—NH,
• Q is a single bond, O, S, CO, SO2, Si(CH3)2, (CH2)p (1≤p≤10), (CF2)q (1≤q≤10), C(CH3)2, C(CF3)2, CO—NH, C(CH3)(CF3) or a substituted or unsubstituted phenylene group, and
• x and y are the molar ratios of the corresponding repeat units, wherein both x and y are greater than 0 and x+y=1
• wherein
• Ar1 is an aromatic ring group selected from a substituted or unsubstituted tetravalent C6-C24 arylene group and a substituted or unsubstituted tetravalent C4-C24 heterocyclic group, wherein the aromatic ring group exists independently, two or more of them form a condensed ring or two or more of them are linked by a single bond, O, S, CO, SO2, Si(CH3)2, (CH2)p (1≤p≤10), (CF2)q (1≤q≤10), C(CH3)2, C(CF3)2 or CO—NH,
• Q is a single bond, O, S, CO, SO2, Si(CH3)2, (CH2)p (1≤p≤10), (CF2)q (1≤q≤10), C(CH3)2, C(CF3)2, CO—NH, C(CH3)(CF3) or a substituted or unsubstituted phenylene group,
• Ar2 is an aromatic ring group selected from a substituted or unsubstituted divalent C6-C24 arylene group and a substituted or unsubstituted divalent C4-C24 heterocyclic group, wherein the aromatic ring group exists independently, two or more of them form a condensed ring or two or more of them are linked by a single bond, O, S, CO, SO2, Si(CH3)2, (CH2)p (1≤p≤10), (CF2)q (1≤q≤10), C(CH3)2, C(CF3)2 or CO—NH, and
• x, y and z are the molar ratios of the corresponding repeat units, wherein all of x, y and z are greater than 0 and x+y+z=1.