Preparation of vinylpyridine irradiation‐grafted poly(4‐methyl‐pentene‐1) membrane for oxygen enrichment

By adjusting the casting conditions, the oxygen permeabilities of poly(4‐methyl‐pentene‐1) (TPX) membranes prepared in this study are in the range of 2.91–7.14 × 10−9 cm3(STP) cm/cm2 s cm Hg and permeability ratio of O2/N2 between 2.7 and 4.4. To increase O2N2 selectivity, the vinylpyridine is γ‐ray irradiation‐grafted onto the substrate–TPX membrane. The factors that affect the structure and performance of the grafted membrane considered are: tightness of substrate, kind of solvent for grafting monomers, irradiation conditions, total irradiation dose, and operating temperature and pressure. The O2/N2 selectivities of grafted TPX membranes are significantly improved comparing to that of nongrafted TPX membranes. For example, an O2 permeability of 35.6 × 10−10 cm3(STP) cm/cm2 s cm Hg and an O2/N2 permeability ratio of 7.5 for the grafted membrane can be obtained.