Self-assembly of POSS-containing block copolymers: Fixing the hierarchical structure in networks

A series of P(MMA-co-GMA)-b-PMAPOSS block copolymers (BCPs) were synthesized by ATRP. The BCPs contain FOSS (polyhedral oligomeric silsesquioxane) as a pendant unit on a particular polymer block chain. In selective solvents, the BCPs self-assemble to form ordered micellar-like structures. Spherical, cylindrical or vesicle-like morphologies were produced by tuning the BCP and mixed solvent compositions. Crosslinking of the BCP by the reaction of the glycidyl groups in the P(MMA-co-GMA) block of the micelle shell (GMA = glycidyl methacrylate) with a diamine results in a long-range structure ordering. The hexagonally packed cylindrical arrangement of the BCP networks was revealed by SAXS and TEM. The hierarchical, ordered structure of the FOSS-containing hybrids was fixed by crosslinking. In addition, transient physical gels were prepared from triblock copolymers with outer MAPOSS blocks, and their rheological behavior was investigated. (C) 2013 Elsevier Ltd. All rights reserved.