Pervaporation characteristics of ethylene–vinyl acetate copolymer membranes with different composition for recovery of ethyl acetate from aqueous solution

The degree of crystallization, surface property and density of ethylene–vinyl acetate (EVA) copolymer membranes with different vinyl acetate (VA) content were measured by differential scanning calorimetry (DSC), contact angle meter and pycnometer. The pervaporation (PV) characteristics of the EVA copolymer membranes for recovery of ethyl acetate (EA) from aqueous EA solutions have been investigated. The separation factor (α) decreased with increasing VA content from 26 wt.% (EVA26) to 100 wt.% (poly vinyl acetate, PVAc) in EVA copolymer membranes. A maximum EA flux (JEA,max) of EVA membrane with 38 wt.% VA content revealed for 2.5 wt.% aqueous EA solution at 30 °C, JEA,max reached to 550 g/(m2 h) and α was to 118. These PV characteristics of EVA membranes were explained in terms of the crystallinity of EVA copolymer and the affinities between EA or water and VA segment in EVA copolymer membrane. Experimental results also show that both α and JEA increased with increasing feed temperature and feed concentration.