Preparation of anion exchange membranes from BPPO and dimethylethanolamine for electrodialysis

Abstract

In this research work, the synthesis of anion exchanges membranes (AEMs) from brominated poly (2, 6-dimethyl-1, 4-phenylene oxide) (BPPO) and dimethyethanolamine (DMEA) has been investigated for electrodialysis (ED) application. Fourier transform infrared spectroscopy was used to confirm the functional groups in the membranes. The morphology of the prepared membranes was investigated by scanning electron microscopy. Physiochemical and electrochemical properties of the prepared membranes were studied in detail. The membranes possess ion exchange capacity of 0.66 mmol/g to 1.38 mmol/g, water uptake of 11.60 % to 48.50 %, volume expansion ratio of 8.58 % to 20.21 %, tensile strength of 32.52 MPa to 49.22 MPa and transport number of 0.94 to 0.98. These membranes have higher chemical stability in alkaline medium than QPPO membrane (quaternized with trimethylamine) at room temperature. The membranes DMEA-10 and DMEA-15 were selected for NaCl desalination by ED with a lab-scale electrodialysis cell at constant applied voltage. The prepared membranes DMEA-10

Controllable Cross‐Linking Anion Exchange Membranes with Excellent Mechanical and Thermal Properties

“…Whereas with increasing the IEC, the water absorption and swelling rate of the AEMs would also be fortified, thereby reducing the dimensional stability of the ion exchange membrane. For example, Khan et al had prepared a kind of quaternary ammonium bromide polyphenylene oxide (BPPO) AEM, which demonstrated good mechanical properties, for example, a tensile strength of 32.52–49.22 MPa, but a high swelling rate of 20.41% when the IEC of the membrane was 1.47 mmol g −1 . Clark et al made a series of norbornene ion exchange membranes, in which dicyclopentadiene (DCPD) was used as cross‐linker to increase the dimensional stability of ion exchange membrane.…”

Fabrication of N1-butyl substituted 4,5-dimethyl-imidazole based crosslinked anion exchange membranes for fuel cells

“…3 Lai et al prepared the phenolphthalein-containing poly(arylene ether sulfone)s crosslinked AEMs showed a high IEC of 1.91 mmol g À1 while the swelling ratio was less than 15%. 13 Unfortunately, it has been reported that the aryl ethercontaining crosslinked AEMs, such as poly(phenylene oxide) (PPO) 14,15 and polysulfone (PSF), 16,17 would be severely degraded by cleavage of the C-O bonds via ether hydrolysis and/or QA group hydrolysis under high pH conditions. 18,19 Besides, except from the ionic conductivity of AEMs, chemical stability, especially for functional groups, is still considered to be a tough challenge.…”

Reinforced anion exchange membrane based on thermal cross-linking method with outstanding cell performance for reverse electrodialysis

“…11,12 As shown in previous studies, polystyrene (PS) and poly(phenylene oxide) (PPO) have been widely used as matrix polymers for the synthesis of hydrocarbon-based ionomers because of their low cost, good mechanical properties, and easy processibility. 4,[13][14][15][16][17][18][19][20][21] PS and PPO are easily converted to chloromethylated PS (cmPS) and brominated PPO (brPPO), which are precursor polymers of quaternary-aminated PS (QPS) and quaternary-aminated PPO (QPPO), respectively. However, aer the quaternization reaction of cmPS and brPPO, QPS and QPPO showed lower mechanical and chemical stability due to increased water uptake; thus, QPS and QPPO are typically used in the cross-linked ionomer form.…”