Synthesis of amphiphilic nanoparticles and multi-block hydrophilic copolymers by a facile and effective “living” radical polymerization in water

“Living” radical polymerization (LRP) has been a facile method for the preparation of polymers with controlled molecular weights and low polydispersities. This work presents a simple and efficient LRP technique using copper(II) acetate (Cu(OAc)2) and hydrophilic 4-cyano-4-((diethylcarbamothioyl)thio) pentanoic acid (MANDC-COOH) to prepare amphiphilic nanoparticles and multiblock polymers in water. By this technique, firstly, soap-free emulsion polymerization was carried out successfully by using the synthesized poly(poly(ethylene glycol) monomethyl ether methacrylate) (PPEGMA) as the macro-initiator and emulsion stabilizer, and methyl methacrylate (MMA) or styrene (St) as the hydrophobic monomer by sequential addition, which permits amphiphilic copolymer self-assembling in situ into sphere nanoparticles; secondly, a hydrophilic deca-block homopolymer, poly(potassiumsulfopropylmethacrylate) (PSPMA) and an alternating hepta-block copolymer, poly(potassiumsulfopropylmethacrylate)-alt-poly(sodium methacrylate) (PSPMA-alt-PNaMA) by sequential addition of monomers were synthesized smoothly in water for the first time.