Novel polymeric membranes for separation of hydrocarbons

The search for polymeric materials capable of separating lower paraffins from the corresponding olefins revealed that polyphenyleneoxide (PPO) and some PPO-based copolymers possess rather high selectivity and permeability in separation of the gaseous mixtures containing methane and ethane, ethylene and ethane, or propene and propane (selectivities αCH4/C2H6 ≅ 12, αC2H4/C2H6 ≅ 4–5 at 20–30°C, and αC3H6/C3H8 ≅25–70 at 50°C were obtained). Solubilities of these hydrocarbons in PPO and its copolymers were measured, and were found to change in the sequence CH4