Recent advances in the synthesis and structure-property relationships of ammonium ionenes

Ionenes are ion-containing polymers that have quaternary nitrogen atoms in the macromolecular main chain as opposed to a pendant site. They are synthesized through a Menshutkin reaction of ditertiary amines and alkyl dihalides. This review focuses on the synthesis and structure-property relationships of ammonium ionenes, which were first synthesized in 1933. Since then, many researchers have investigated the effect of charge density of novel ionene families on polymer properties, such as viscosity and dynamic mechanical behavior. In particular, emphasis is placed on the properties of non-segmented and segmented ionene polymers. Although this investigation focuses largely on linear ionenes, branched and cross-linked ionenes will also be discussed.