Preparation and characterization of EVOH/PVP membranes via thermally induced phase separation

Poly(ethylene-co-vinyl alcohol) with ethylene content of 44 mol% (EVOH44)/polyvinylpyrrolidone (PVP) (K30) membranes were prepared via thermally induced phase separation (TIPS). Poly(ethylene glycol) with average number weight of 300 (PEG300) was used as diluent. Differential scanning calorimetry (DSC) and attenuated total reflectance infrared (ATR-Fr-IR) spectra were used to investigate the compatibility of EVOH44 and PVP (K30). From disappearance of the melting peak of EVOH, T-g of PVP in DSC, the shift of PVP carbonyl and C-O bonds of EVOH in ATR, it was indicated that they were compatible. The effects of PVP content on phase diagram, PVP distribution and membrane morphology were studied. It was found that the binodal point shifted to higher temperature and proportion of PVP between polymer matrix to pore surface decreased with PVP content increasing. It was also found that the pore size of the membranes increased as PVP content increased. The hydrophilicity and protein adsorption properties of EVOH/PVP membranes were also measured, the results indicated that they had better hydrophilicity and protein antifouling property compared with pure EVOH membrane. (c) 2006 Elsevier B.V. All rights reserved.