Chloromethylation and Amination of Polymers (for AEM)

Chloromethylation (generally haloalkylation) of polymeric membranes followed by an amination reaction has been widely used for preparation of anion exchange membranes (AEMs). Significant efforts have been made to prepare AEMs from insoluble polymeric films such as polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF). Such AEMs are typically prepared by grafting vinyl monomers such as styrene onto polymeric films and subsequent chloromethylation and amination modifications. Also, soluble polymers such as polystyrene (PS), polyether sulfone (PES), polyether ketone (PEK), or their blends or block copolymers have been widely used for preparation of AEMs. In such case, charged moieties can be introduced to the dissolved polymer via chloromethylation and amination reactions, either prior to the casting of polymer or after the casting into a film. Posttreatment, i.e., cross-linking of membranes, is often required to improve the chemical...