Nano-scaled ordering of hyperbranched and star-hyperbranched polymers

Hyperbranched polystyrenes (HPS) were prepared by living radical polymerization of 4‐vinylbenzyl N,N‐diethyldithiocarbamate (VBDC) as an inimer under UV irradiation. These HPS exhibited large amounts of photofunctional diethyldithiocarbamate (DC) groups on their outside surfaces. We derived star‐HPS (SHPS) by grafting from such HPS macroinitiator with methyl methacrylate (MMA) or ethyl methacrylate (EMA). The ratios of radius of gyration to hydrodynamic radius Rg/Rh for HPS and SHPS in tetrahydrofuran (THF) were in the range of 0.74–0.90 and 1.05–1.12, respectively. HPS and SHPS behaved in a good solvent as hard and soft spheres, respectively. We demonstrated the structural ordering of both branched polymers in THF through small‐angle X‐ray scattering (SAXS), by varying the polymer concentration. As a result, HPS and SHPS formed face‐centered‐cubic (fcc) and body‐centered‐cubic (bcc) structures, respectively, near the overlap threshold (C*). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3340–3345, 2006