Synthesis and viscoelastic behavior of multiarm star polyelectrolytes

Star-shaped poly(tert-butyl acrylate)s were synthesized by the atom transfer radical polymerization (ATRP) method. Subsequently, star-shaped poly(acrylic acid)s were induced by hydrolysis of tert-butyl units. The structural ordering of these stars was investigated through small-angle X-ray scattering (SAXS) in aqueous solution. Star with f = 30 and f = 97 formed a bee structure above the overlap threshold (C*). The viscoelastic behavior of the stars was also investigated. This system showed the transition from a Maxwellian fluid of a weak liquid ordering to a solid of macrolattice structure with increasing the polymer concentration. This result reflected the stronger interaction among star polyelectrolytes at higher polymer concentration.