A series of novel side-chain-type anion exchange membranes (AEMs) composed of poly (arylene ether sulfone)s backbone and pendent imidazolium-functionalized polyphenylene oxide (PPO) was prepared via chemical grafting, bromination, functionalization and alkalization. The chemical structure of the as synthesized copolymers was confirmed by H-1 NMR spectroscopy. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the morphology of the AEMs. The densely functionalized side chains are found to be beneficial to the formation of ion clusters, as demonstrated by TEM. As a result, the hydroxide conductivity of the PAES-x-IMPPO membranes was 78.8 mS cm(-1) at 80 degrees C. Moreover, the AEMs also exhibit robust mechanical properties, good thermal stability and reasonable alkaline stability. An open circuit voltage (0.98 V) of H-2/O-2 alkaline fuel cell using PAES-15-IMPPO at 60 degrees C can be an indicative of low fuel crossover. The maximum power density was 56.8 mW cm(2) at a current density of 125 mA cm(2) without optimization. (C) 2016 Elsevier B.V. All rights reserved.