Hydroxide‐ion transport and stability of diblock copolymers with a polydiallyldimethyl ammonium hydroxide block

Base‐stable amphiphilic diblock copolymers with a polydiallyl dimethyl ammonium hydroxide block were synthesized and characterized to quantify hydroxide‐ion transport in the hydrated state; polystyrene was the hydrophobic block. The challenge of synthesizing a copolymer comprising blocks with very different solubility behaviors was addressed by a combination of reversible addition fragmentation chain transfer polymerization and ion metathesis. Both monomers used in the polymerization are commercially available on industrial scales. Hydroxide‐ion conductivities of 0.8 mS/cm were achieved in hot‐pressed membranes immersed in water at room temperature despite relatively low water uptake (4.2 water molecules per hydroxide ion). The stability of the polydimethyl ammonium hydroxide chains was investigated in 2 M NaOD at 60 °C. 1 H NMR spectroscopy studies showed no detectable degradation after 2000 hours. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 2243–2248