|254. Breiner, T.; Kreger, K.; Hagen, R.; Häckel, M.; Kador, L.; Müller, A.H.E.; Kramer, E.J.; Schmidt, H.-W.: Blends of Poly(methacrylate) Block Copolymers with Photoaddressable Segments, Macromolecules 40, 2100 (2007)|
The paper presents the synthesis of azobenzene-functionalized block copolymers based on a poly(methyl methacrylate) (PMMA) segment and an azobenzene-functionalized poly(hydroxyethyl methacrylate) segment, and a basic study of blending these block copolymers with homopolymers is given. Two diblock copolymers, prepared via different routes, were synthesized by a living anionic polymerization followed by a polymer analogous reaction to attach the azobenzene side groups. Self-assembly of the block copolymers resulted in phase-separated morphologies on the nanometer scale. The photoaddressable azobenzene segments are dispersed in the PMMA matrix and locally confined. Special focus is given to the preparation and characterization of block copolymer blends with PMMA homopolymer in order to dilute the phase-separated azobenzene morphology and reduce the optical density while maintaining the confinement. The block copolymer blends were characterized with respect to their morphology and first holographic experiments were performed.