Selective betainisation of tertiary amine methacrylate block copolymers

2-(Dimethylamino)ethyl methacrylate (DMAEMA) was block copolymerised in turn with three other tertiary amine methacrylate comonomers using group transfer polymerisation; the DMAEMA residues of each of these diblock copolymers wereselectively betainised using propane-1,3-sultone under mild conditions to yield a series of novel water-soluble sulfobetaine block copolymers which exhibit reversible pH- and temperature-induced micellisation.