Branched polyamide/poly (acrylonitrile) blend membranes: synthesis, characterisation and pervaporation applications

Herein, a novel branched polyamide (BPA-1and BPA-2) was synthesised by direct polycondensation using branched polyethyleneimine and two different dicarboxylic acids (adipic acid and Hexafluoroisopropylidene bis benzoic acid) as monomers. The newly developed BPA was blended with poly (acrylonitrile) (PAN) separately at ratio of 3:1 (BPA/PAN) to form a branched BPA/PAN membrane via the solution-casting method. The prepared membrane was characterised using FTIR, X-ray, SEM and TGA and so that used for the dehydration of alcohols by pervaporation process. The experimental results revealed that the permeation flux of the BPA/PAN membrane increased with increasing feed ethanol concentration and feed temperature, but an increase in the number of carbon atoms inalcohol results in an increase in the permeation rate. The best separation performance could be achieved for the BPA-2/PAN membrane at 60°C for 80% ethanol in the feed with a total flux of 925 g m−2 h−1 and a separation selectivity of 1696.