Preparation of poly(ether-block-amide)/poly(amide-co-poly(propylene glycol)) random copolymer blend membranes for CO2/N2 separation

A series of poly(amide- co -poly(propylene glycol)) (PA-PPG) random copolymers with different content of PPG were designed by polycondensation reaction. These random copolymers were blended up to 60% with commercially available Pebax 2533. The blend membranes were characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM). Gas permeation properties of these blend membranes were investigated using five single-gases (CO 2 , H 2 , O 2 , CH 4 , and N 2 ) at different temperature of 25–55°C and 1.0 atm. The impacts of content of PA-PPG with different PPG content and operating temperature on CO 2 separation properties of Pebax/PA-PPG blend membranes were studied. The results showed that CO 2 permeability gradually increased with the increasing operating temperature, whereas CO 2 permeability gradually decreased with the increase in content of PA-PPG. CO 2 /N 2 selectivity gradually increased with the increase in content of PA-PPG. In particular, Pebax/PA-PPG (50)–60% displayed excellent CO 2 and O 2 separation properties ( P CO2 = 79.7 Barrer and P O2 = 13.6 Barrer, CO 2 /N 2 = 34.7 and O 2 /N 2 = 5.9) at 25°C and 1.0 atm. POLYM. ENG. SCI., 59:E14–E23, 2019. © 2018 Society of Plastics Engineers