Effect of reactive diluent on gas separation behavior of photocurable acrylated polyurethane composite membranes

Abstract

In this study, the effects of the type and content of reactive diluents on the permeation/separation of carbon dioxide/nitrogen (CO 2 /N 2 ) through acrylate-terminated polyurethane (APU)-acrylate/acrylic diluent (APUA) composite membranes was investigated. A series of APUs based on poly(ethylene glycol) (PEG)-1000 g mol −1 , toluene diisocyanate, and 2-hydroxyethyl methacrylate was synthesized and then diluted with several reactive diluents. The results obtained from differential scanning calorimetry (DSC) and Fourier transform infrared analyses showed that the microphase interference of hard and soft segments increased with increasing reactive diluent content. Furthermore, with increasing alkene double bond of reactive diluents, the degree of phase separation increased, which might be due to the higher gel content of APUAs. APUAs were used as top selective layer on PS/PSF as the support layer to obtain composite membrane. Field emission scanning electron microscopy micrographs revealed that APUAs penetrated into the support layer, leading to strong interfacial adhesion between APUA and support layers. The gas permeation experiments indicated that the gas permeability decreased, while the CO 2 /N 2 selectivity increased with increasing reactive diluent content due to the enhancement of crosslinking density of APUAs. Moreover, the reactive diluent with high polarity, for example, acrylonitrile monomer, exhibited higher CO 2 /N 2 selectivity due to the improvement in solubility of CO 2 in APUA, while the permeability was retained compared with other reactive diluents. The thickness of APUA selective layer exhibited expectedly opposite effect on permeability and selectivity; however, the increment in selectivity is higher than the reduction in permeability when the thickness decreased from 50 to 10 μm.

Bio‐based photo‐curable polyurethane composites

“…Molavi et al, 19 studied the behavior of APUA composite with various diluting agents on absorptivity and specificity of different gasses through influencing ratio, type and number of double bonds in diluent. APUA was prepared from APU, diluting agents [HEMA, ethylene glycol dimethacrylate (98%), AAC (99%), glycidyl methacrylate (97%), acrylonitrile (99%), methacrylic acid (99%) and methyl methacrylate (MMA) (99%)], PI (BP) and accelerator MDEA then cured with 1000 W‐UV‐light of 365 nm wavelength on microporous polysulfone (PSF) to obtain film.…”

“…Gadgeel et al,70 synthesized thermally stable UV-curable biodegradable PUA from isosorbide (IS) and α-ketoglutaric acid (KA). KA, IS, ethanol, p-TSA and KOH were reacted to prepare α-ketoglutaric acid-Molavi et al,19 studied the behavior of APUA composite with various diluting agents on absorptivity and specificity of different gasses through influencing ratio, type and number of double bonds in diluent.APUA was prepared from APU, diluting agents [HEMA, ethylene (PSF) to obtain film. Structure and various properties such as permeability, selectivity, viscosity and gel content influenced by diluents were confirmed through Fourier transform infrared (FTIR)-attenuated total reflection analysis.…”