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

Abstract

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 (CO2, H2, O2, CH4, and N2) 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 CO2 separation properties of Pebax/PA‐PPG blend membranes were studied. The results showed that CO2 permeability gradually increased with the increasing operating temperature, whereas CO2 permeability gradually decreased with the increase in content of PA‐PPG. CO2/N2 selectivity gradually increased with the increase in content of PA‐PPG. In particular, Pebax/PA‐PPG (50)–60% displayed excellent CO2 and O2 separation properties (PCO2 = 79.7 Barrer and PO2 = 13.6 Barrer, CO2/N2 = 34.7 and O2/N2 = 5.9) at 25°C and 1.0 atm. POLYM. ENG. SCI., 59:E14–E23, 2019. © 2018 Society of Plastics Engineers