Modification of poly(ether imide) membranes with brominated polyvinylpyrrolidone

The work refers to the hydrophilization of microporous poly(ether imide) (PEI) membranes by coating with brominated poly(vinylpyrrolidone) (BrPVP). The PEI microporous membranes were first aminated with poly(ethylene imine) (Pei) and then coated with BrPVP. PVP layer on the membrane prepared from a high molecular weight BrPVP was resistant against washing out with aqueous solutions, which resulted from the stabilization of the gel layer, whereas the layers prepared from unbrominated or low molecular weight BrPVP were not completely stabilized. Separation profiles of resulting membranes can be tailored according to the requirements of application. BrPVP was prepared by the reaction of PVP with bromine or hydrobromic acid. It was possible to prepare BrPVP containing large amounts of bromine, which was rather strongly fixed to the PVP chain. The analysis of the products of the same reaction carried out with 1-ethyl-2-pyrrolidone (EP) (a low molecular weight model of PVP) indicated that the BrPVP comprises addition complexes between HBr molecules and carbonyl groups of PVP. The new PVP coated membranes are promising candidates for the blood contacting applications.