Synthesis of amphiphilic block-gradient copolymers of styrene and acrylic acid by nitroxide mediated polymerization
Abstract
We present an overview on synthesis of amphiphilic ionic block-gradient copolymers of styrene and acrylic acid by means of one step direct Nitroxide Mediated Polymerization (NMP) and their characterization. The copolymers comprise a block of poly(acrylic acid) and one or two terminal blocks that include co-monomer units of styrene and acrylic acid in variable proportion. Using 1H NMR the gradient sequence of the poly(acrylic acid-co-styrene) copolymer block has been confirmed. In contrast to diblock copolymers of styrene and acrylic acid, that are known to form in aqueous environment “frozen” aggregates with glassy poly(styrene) core, the novel block gradient copolymers exhibit stimuli-responsive aggregation behavior, as was demonstrated by subsequent studies. This feature makes them very promising for design of a large variety of smart functional materials. © Pleiades Publishing, Ltd., 2015.