Synthesis of (Poly(chloroethyl vinyl ether)-g-polystyrene)comb-b-(poly(chloropyran ethoxy vinyl ether)-g-polyisoprene)comb Copolymers and Study of Hyper-Branched Micelle Formation in Dilute Solutions

Poly(styrene)comb- b -poly(isoprene)comb copolymers having a heterofunctional polyvinyl ether diblock backbone were synthesized by the grafting onto method. Their synthesis involves in a first step the selective coupling reaction of polystyryllithium chains onto the reactive chloroether functions of a poly(chloroethyl vinyl ether) first block while the second block poly(pyranethoxy vinyl ether) remains unchanged, yielding Poly(styrene)comb with a poly(pyranethoxy vinyl ether) tail. In a second step, living polyisoprenyllithium chains are grafted onto the second block previously modified to introduce reactive chlorobutyl functions. The obtained high molar masses PScomb- b -PIcomb copolymers exhibit a low polydispersity and a controlled number of branches. Their characteristics and behavior were further studied as isolated objects using imaging technique such as atomic force microscopy and using light scattering in a good solvent for PS and PI moieties, and in a selective solvent of PIcomb blocks. The PScomb- b -PIcomb copolymers adopt a cylindrical conformation in good solvent and self-assemble in micelles by association of the combPS blocks in heptane.