Preparation of anion exchange membranes from BPPO and dimethylethanolamine for electrodialysis

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 and DMEA-15 showed better performance than the commercial anion exchange membranes Neosepta AMX under the identical conditions.