The effects of diol and diamine aromatic chain extenders on the gas permeation properties of the polyurethane membranes
Paper ID : 1215-MST2015-FULL
Ali Pournaghshband Isfahani1, Behnam Ghalei2, Morteza Sadeghi *3, Easan Sivaniah4
1Chemical Engineering Department, Isfahan University of Technology, Isfahan 84156-8311
2Institute for Integrated Cell-Material Science (iCeMS), Kyoto University, Kyoto 606-8501
3isfahan university of technology
4Institute for Integrated Cell-Material Science (iCeMS), Kyoto University,
A series ofpolyurethane and polyurethane-urea were synthesized to investigate the effects of diol and diamine aromatic chain extenders on the phase separation and gas permeation properties.Polymers were prepared usingpolytetramethylene glycol (PTMG, 2000 g/mol),isophoronediisocyanate (IPDI) anddifferent chain extenders by adjusting the molar ratio of 1:3:2, respectively. The chemical structure of prepared membranes were confirmedusing NMR and FTIR. The pure gas permeabilities were measured at 25oC and 4bar. The FTIR and DSC results show more phase separated structure for o-tolidine based polyurethane-urea sample compared to 4,4-dihyroxybiphenol polyurethane one. Also, the presence of ethereal groups in the 4,4'-diaminodiphenyl ether- based polyurethane urea causes more phase separated structures compared to the similar structure synthesized polyurethane urea by o-tolidine. The results of the permeability tests show the highest permeability for 4,4-diaminidiphenyl ether-based polyurethane-urea, up to 82 Barrer for CO2, while the lowest gas permeability belongs to 4,4'-dihydroxybiphenol-based polyurethane, up to 16 Barrer, which are in good agreements with the phase separation results. Finally, in this study we can find that segregation between the hard and soft segments might be manifested more by the extent of inter-chain hydrogen bonding rather than other factors, such as hindrance effect or rigidity of the hard segments.
Polyurethane, Membrane, Gas separation, aromatic chain extender
Status : Paper Accepted (Poster Presentation)