Photo-curable acrylate polyurethane as efficient composite membrane for CO2 separation

The current investigation was to present composite membranes with strong interfacial adhesion between top polymeric selective layer and the bottom micro-porous support layer with appropriate gas permeation behavior and practically suitable processing characteristics. To this end, a series of acrylate-terminated polyurethanes (APUs) based on poly (ethylene glycol) (PEG) with different molecular weights (Mn) of 600, 1000, 1500, 2000 and 4000 g/mol, toluene diisocyanate (TDI), and 2-hydroxyethyl methacrylate (HEMA) were synthesized. Composite membranes were prepared with UV-curable acrylateterminated polyurethane/acrylate diluent (APUAs) as selective layer and polyester/polysulfone (PS/PSF) as support layer. FTIR-ATR and DSC analyses indicated that the micro-phase separation of soft and hard segments increased by increasing the molecular weight of PEG. The experimental results revealed that the gas permeation behavior of APUA was mostly similar with rubbery materials; however, its morphological characteristics such as degree of micro-phase separation and crosslinking density are influential for the overall gas permeation behavior. It was revealed that the adhesion of APUA membranes to support layer was found to be strong and did not deteriorate after swelling in water. APUA composite membranes also exhibited very good long term gas permeation stability due to its stable structure originated from the cross-linked network. (C) 2018 Published by Elsevier Ltd.