In this paper

poly(amide-6-β-ethylene oxide) (PEBA1657) copolymer was used to prepare multilayer polyetherimide (PEI)/polydimethylsiloxane (PDMS)/PEBA1657/PDMS composite membranes by dip-coating method. Permeation behaviors of ethylene

ethane

propylene

propane

n-butane

methane and nitrogen through the multilayer composite membranes were investigated over a range of operating temperature and pressure. The permeances of light hydrocarbons through PEI/PDMS/PEBA1657/PDMS composite membranes increase with their increasing condensability

and the olefins are more permeable than their corresponding paraffins. For light hydrocarbons

the gas permeances increase significantly as temperature increasing. When the transmembrane pressure difference increases

the gas permeance increases moderately due to plasticization effect

while their apparent activation energies for permeation decrease.