Abstract: Polymer/liquid crystal composite membranes containing poly(cis-butadiene)(PB)and diethylene glycol bis-4-(4'-ethoxybenzoyloxy) benzoate(DEBEB)with two transitionmesophases were prepared for the first time and their oxygen enrichment properties were investigated.The oxygen permeability of the composite membrane with 10% weight content ofDEBEBliquid crystal exhibited several times greater than that of the PBmembrane at roomtemperature.Relationship between permeability coefficients and temperatures was characterized by N-shape curves,that is,the permeability coefficients first increased,followed by decreasing,and then increased again with increasing temperature continuously.We interpretthis result as effect of phase behavior of the liquid crystal and morphology of the compositemembranes on the permeabilities.

Key words: Gas separation membrane, Oxygen enrichment membrane, Polymer/liquid crystal composite membrane