Preparation and gas permeation of composite carbon membranes from poly(phthalazinone ether sulfone ketone)

Composite carbon membranes were prepared from poly(phthalazinone ether sulfone ketone) (PPESK) by incorporating with polyvinylpyrrolidone (PVP) or zeolite (ZSM-5) through stabilization and pyrolysis processes. The thermal stability of composite polymeric membranes was measured by thermal gravimetric analysis. The resultant composite carbon membranes were characterized by scanning electron microscopy, X-ray diffraction and gas permeation technique, respectively. The results illustrated that the thermal stability of composite polymeric membranes was enhanced by addition of ZSM-5 or reduced by PVP. For ZSM-5 or PVP composite carbon membranes prepared at 650 °C, the O2 permeability is 199.70 Barrer or 124.89 Barrer, and the O2/N2 selectivity is 10.3 or 4.2, respectively. Compared with carbon membranes from pure PPESK, the O2 permeability of ZSM-5 or PVP composite carbon membranes increases by 18.5 or 11.6 times, together with the O2/N2 selectivity decreasing by 35.2% or 73.6%, respectively. The gas separation mechanism of composite carbon membranes is molecular sieving. Adsorption effect also plays a significant role for CO2 permeating through ZSM-5 composite carbon membranes.