Azeotropic Atom Transfer Radical Polymerization of Hydroxyethyl Methacrylate and (Dimethylamino)ethyl Methacrylate Statistical Copolymers and Block Copolymers with Polystyrene

Statistical copolymers of hydroxyethyl methacrylate (HEMA) and (dimethylamino)ethyl methacrylate (DMAEMA) were synthesized by atom transfer radical polymerization (ATRP) at the azeotrope in N, N -dimethylformamide (DMF) with controlled molecular weights and molecular weight distributions (generally <1.2). Since the polymerization takes place at the azeotrope, the polymer composition is fixed at the monomer feed composition (HEMA molar composition = 0.718), and there is little compositional drift with total monomer conversion. Poly(HEMA- co -DMAEMA) copolymers were also successfully synthesized from a polystyrene macroinitiator previously made by ATRP. Solution-cast thin films of polystyrene- b -poly(HEMA- co -DMAEMA) amphiphilic diblock copolymers exhibit ordered and periodic nanoscale structures with morphologies that depend on the relative volume fractions and casting solvent used.