Pervaporation separation of aqueous alcohol solution through a carbazole-functionalized norbornene derivative membrane using living ring-opening metathesis polymerization

Living ring-opening metathesis polymerization (ROMP) of a norbornene derivative containing carbazole group, 5-(N-carbazolyl methylene)-2-norbornene (CbzNB), was carried out to prepare pervaporation membranes for aqueous alcohol solution separation. The linear dependence of the number average molecular weight (Mn¯) on the [M]/[I] ratio ([M], monomer concentration; [I], initiator concentration) and low polydispersity (PDI) demonstrated a living polymerization of CbzNB. Hydrogenation of poly(CbzNB), poly(H-CbzNB) increased the polymer thermal stability. The water molecules preferentially permeate through the poly(H-CbzNB) membranes. The feed compositions, degree of swelling and molecular size effects of the alcohols on the pervaporation performances were investigated. The separation factor and the permeation rate increase with increasing ethanol concentration in the feed.