Comparative assessment of hydrocarbon separation performance of bulky poly(urethane-urea)s toward rubbery membranes

• Published in: Journal of natural gas science and engineering Vol. 98; p. 104356
• Main Authors: Fakhar, Afsaneh, Sadeghi, Morteza, Dinari, Mohammad, Lammertink, Rob
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2022
• Subjects: Aliphatic side chains; Aromatic side chains; Hydrocarbon separation; Phase separation; Polyurethane membranes; Hydrocarbon separation; Polyurethane membranes; Phase separation; Aromatic side chains; Aliphatic side chains
• ISSN: 1875-5100
• DOI: 10.1016/j.jngse.2021.104356

In the present study, two seriess of poly (urethane urea)s (PUUs) membranes containing aromatic and aliphatic side chains with different sizes were used for separation of higher hydrocarbons from methane. Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetery (DSC), fractional free volume (FFV) estimation, and gas permeation measurements (CH4, C2H6, C3H8) were done to characterize the membranes. Bulkier or longer side chains in aromatic and aliphatic substituted PUUs provided enhanced phase separation, lower glass transition temperature and higher gas permeability. Fractional free volume (FFV) as a significant factor controlling gas separation had a reverse trend in both series by increasing the size of side chains. The main findings confirmed the capability of higher phase separated PUUs for hydrocarbon separation. The highest permeability and selectivity was obtained by the longest side chain based PUU with propane permeability of 186 barrer and propane/methane selectivity of 6.51. [Display omitted] •Two series of poly (urethane-urea)s (PUU)s with various structures were synthesized.•The separations of C2H6/CH4 and C3H8/CH4 were carried through the PUU membranes.•Higher phase separation was obtained by bulkier and longer side chain-based PUUs.•Efficient separation of more condensable hydrocarbons was obtained.•The longest aliphatic side chain based PUU provide the best hydrocarbon separation.