Synthesis and characterization of poly(styrene-b-n-butyl acrylate-b-styrene) triblock copolymers using a dialkoxyamine as initiator

This study investigates the ability of a novel difunctional alkoxyamine based on N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide (SG1) to serve as initiator for the controlled radical polymerization of styrene (S) and n-butyl acrylate (nBuA), The efficiency of this initiator was checked using three different methods. After we set up the conditions best suited to the synthesis of perfectly difunctional poly(n-butyl acrylate)(PnBuA) samples, well-defined poly(styrene-b-n-butyl acrylate-b-styrene) triblock copolymers could be obtained by sequential polymerization of the corresponding monomers. However, a loss of control of the targeted structure was observed whenever the conversion of styrene exceeded 40%.