Ys. Kang et al., PERVAPORATION OF WATER-ETHANOL MIXTURE THROUGH HYDROPHILICALLY MODIFIED POLYIMIDE MEMBRANE, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 224, 1993, pp. 137-146
Polyimide of pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (OD
A) was hydrophilically modified by partial replacing of ODA with 3,5-d
iaminobenzoic acid (DABA) containing a carboxylic group with two amine
groups. Pervaporation experiments of water/ethanol mixture were perfo
rmed and the results demonstrated that both flux and permselectivity i
ncrease simultaneously with increasing DABA content in polyimide backb
one. From the sorption and temperature-dependent permeation behavior,
it could be concluded that the diffusivity of permeant plays a major r
ole in determining the pervaporation performance rather than the solub
ility.