Donor-acceptor diblock copolymers based on PPV and C60:: Synthesis, thermal properties, and morphology

An improved synthetic method to nitroxide end-capped poly(p-phenylenevinylene)s is presented. The nitroxide-functionalized PPVs are extended with a second coillike block by employing them as macroinitiators in a nitroxide-mediated radical polymerization (NMRP) of monomers like styrene, 4-chloromethylstyrene, 4-vinylpyridine, and n-butyl acrylate. The observed thermotropic properties and morphology of films based on the rod-coil diblock copolymers are identified and described. Some of the block copolymers are subsequently subjected to a coupling with C-60 to incorporate electron-accepting properties into these PPV-based diblock copolymers. For this, a statistical copolymer built from styrene and azidomethylstyrene was used as the second coillike block, making it possible to adjust the built-in ratio of C-60. The morphology and thermotropic properties of films prepared with these diblock copolymers are investigated.