Synthesis of polybetaines with narrow molecular mass distribution and controlled architecture

Polybetaines with narrow molecular mass distribution (Mw/Mn < 1.25) are synthesized directly for the first time; group-transfer polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) yields near-monodisperse precursor polymers which are quantitiatively betainised under unusually mild conditions using 1,3-propanesultone; block copolymerisation of DMAEMA with alkyl methacrylate comonomers, followed by betainisation, leads to hydrophilic–hydrophobic sulfopropylbetaine block copolymers.