Preparation of anion exchange membranes based on pyridine functionalized poly(vinyl alcohol) crosslinked by 1,4‐dichlorobutane

Abstract

ABSTRACTA series of anion exchange membranes [pyridine functionalized‐poly(vinyl alcohol)‐1,4‐dichlorobutane (PVA‐PY‐DLx)] were synthesized by using PVA‐PY as polymer matrix and DL as crosslinker and iodomethane as quaternization reagent. During the experiment, pyridine groups grafted on PVA were transformed into quaternary ammonium group during the formation process of the crosslinked structure and the quaternization routine by iodomethane. The characterization results revealed that the PVA‐PY‐DLx membranes have been successfully prepared and the crystallinity increases with increase of DL. PVA‐PY‐DLx membranes have smooth and uniform morphology. The introduction of crosslinked structure improves the mechanical properties and dimensional stability of the PVA‐PY‐DLx membrane, enhances the alkali resistance. When the mass content of DL was 4.0%, composite membrane had the maximum tensile strength (44.2 MPa), and the OH− conductivity reaches 1.05 × 10−2 S cm−1 at 70 °C. The accelerated aging experiment was carried out in 3 mol L−1 potassium hydroxide (KOH) solution for 120 h at 80 °C, which revealed that the anionic conductivity of PVA‐PY‐DL4.0 membrane retains 79.6% of its initial conductivity, showing better stability of alkali stability. Methanol permeability of PVA‐PY‐DLx membranes was only the 0.37–0.72% of the Nafion‐117 membrane in 3 mol L−1 methanol at 60 °C. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47395.