Polymer Zwitterions with Phosphonium Cations

Polymer zwitterions are of interest for numerous applications, many of which stem from their antifouling properties when used as hydrophilic coatings. However, the chemical compositions of polymer zwitterions remain limited, with synthetic variants most typically comprising ammonium cations. This manuscript describes the synthesis of novel phosphonium-based zwitterionic monomers, accessed by ring opening of substituted propane sultones with aliphatic and aromatic phosphines, and their polymerization by controlled free radical methods. Interestingly, the resultant polymeric phosphonium sulfonates proved soluble in numerous organic solvents, distinguishing them from the solution properties of more typical hydrophilic polymer zwitterions, with tunable and switchable properties made possible by selection of phosphonium R groups. Block copolymers prepared from these tailored phosphonium sulfonate zwitterions highlight their diverse range of solubility and amenability to aqueous polymer assembly.