The gas transport properties of both single and mixed gas systems including CH

4

CO

2

N

2

C

2

H

6

and helium (He) were investigated using novel polymer membranes fabricated

via

solution casting from organic solvents. The fluorinated polytriazole polymers were synthesized through a polycondensation method incorporating hexafluoroisopropylidene the main polymer backbone

with various fluorinated aniline derivatives as side chains. It was observed that the bulky fluorinated aniline derivative groups such as 4-fluoroaniline

2

5-difluoroaniline

4-bromo-2

5-difluoroaniline

and 2

3

4

5

6-pentafluoroaniline significantly influenced the gas separation performance of the polymer membranes

particularly in terms of permeability and selectivity. The membranes exhibited excellent mechanical stability across a wide range of pure CO

2

feed pressures (100-800 psi

1 psi = 6.895 kPa) without signs of plasticization

highlighting their robustness for high-pressure applications. Additionally

the polymer synthesis process is reproducible and can be readily scaled

with each material displaying high solubility in organic solvents such as dimethyl acetamide

chloroform

and

N

-methyl pyrrolidone. Compared to gases such as CH

4

N

2

and C

2

H

6

the newly developed polymer membranes demonstrated superior permeability for CO

2

and He unde

r upstream feed pressures of up to 800 psi. These materials represent a completely novel class of polymer membranes tailored for advanced gas purification technologies. Their enhanced separation performance

particularly for CO

2

removal and He recovery from natural gas streams at high processing pressures

positions them as promising candidates for industrial applications in gas purification and separation.