Separation of water and o-chlorophenol by pervaporation using HTPB-based polyurethaneurea membranes and application of modified Maxwell–Stefan equation

Hydroxyterminated polybutadiene (HTPB) was reacted with 2,4-toluylene diisocyanate (TDI) followed by the addition of 4,4′-diaminodiphenyl sulfone (DADPS) (diamine chain extender) to prepare polyurethaneurea (PUUSD). The prepared polyurethaneurea was cast over glass petridish to obtain polymer membrane. The pervaporation (PV) performance of the synthesized membrane was studied with aqueous o-chlorophenol solution as feed. The polyurethaneurea membranes were found to be selective towards aromatic component with separation factors >250. The total flux as well as those of the individual components was measured. The effects of various parameters, such as feed composition and temperature, membrane thickness on permeate flux and separation factor were determined. The activation energy for o-chlorophenol permeation, calculated from Arrhenius plot, indicated that an increase in hard segment content imposed a restriction to the transport of organic component. The dependencies of the pervaporation fluxes and the concentration of organic component in permeate on its concentration in the feed were established with the calculation based on modified Maxwell–Stefan equation. A very close agreement between experimental and theoretical fluxes was observed.