Synthesis of Block Copolymers of Acrylic Acid and N-Butyl Acrylate under Reversible Chain-Transfer Conditions in a Water-Alcohol Medium

The laws of dispersion polymerization of n -butyl acrylate in an aqueous-alcoholic medium in the presence of a hydrophilic reversible addition-fragmentation chain-transfer poly(acrylic acid)-based polymeric agent with a trithiocarbonate group within the chain are investigated. It is shown that the portioned introduction of the monomer into the synthesis makes it possible to achieve higher maximum conversions. The resulting block copolymers are characterized by a relatively narrow molecular weight distribution and their number-average molecular weight increases linearly with increasing monomer concentration. The obtained dispersions of triblock copolymer poly(acrylic acid)– block- poly( n- butyl acrylate)– block- poly(acrylic acid) have a unimodal particle size distribution that persists after dialysis against water. It is shown that the synthesized dispersions may be used as a polymer matrix for immobilizing zinc oxide nanoparticles and as a polymer precursor in the process of the seeded polymerization of styrene.