Preparation of Well-Defined Poly[(ethylene oxide)-block-(sodium 2-acrylamido-2-methyl-1-propane sulfonate)] Diblock Copolymers by Water-Based Atom Transfer Radical Polymerization

Well-defined poly[(ethylene oxide)-block-(sodium 2-acrylanudo-2-methyl-1-propane sulfonate)] diblock copolymers [P(EO m -b-AMPS n )], have been obtained by water-based ATRP using α-methoxy-ω-(2-methylbromoisobutyrate) poly(ethylene oxide)s (MeO-P[EO] m -Br i B with m ranging from 12 to 113) and CuBr · 2Bpy (Bpy for 2,2'-bipyridyl) as macro-initiator and catalytic complex, respectively. Compared to direct polymerization in water, it has been demonstrated that the water/ methanol (3:1, v/v) mixture is better suited for predicting the final number-average molar mass from the initial monomer-to-macroinitiator molar ratio and achieving a quite narrow polydispersity, even at high monomer conversion (M w /M n ≈ 1.4 at 80% conversion). The effect of temperature, solvent mixture composition and addition of NaCI salt on the polymerization rate and extent of control over the copolymer molecular parameters have been highlighted as well.