DMA measurements were carried out to characterise the storage modulus (E´) of the polymeric membranes, noting that all membranes were synthesised without the addition of plasticisers, fillers or ionic liquids. Figure shows that a relatively high E´ modulus is obtained for the selected cation exchange membranes with values between 10 6 and 10 5 Pa. These values are considered to be relatively high when taking into account that Nafion TM 117 has a storage modulus of around 10 8 Pa under the same dry conditions. As expected, the introduction of the styrene group to the polymer backbone increases the storage modulus as is observed by the approximately 6-fold increase in modulus at 1Hz