Liquid–Solid Transition and Crystallization of Mixtures of Frozen and Dynamic Star-Like Polymers

Abstract

Spherical polymeric micelles were formed in water by poly(ethylene oxide) end-capped with small hydrophobic chains. These star-like polymers showed dynamic arm exchange, but could be transformed into frozen star polymers by in situ UV irradiation. The effect of adding dynamic star polymers on the liquid–solid transition and crystallization of frozen star polymers was studied using small-angle X-ray scattering and rheology. Frozen star polymers produced with 112 arms showed a liquid–solid transition in dense suspensions that was only weakly modified when half of the polymers was replaced by dynamic star polymers. Frozen star polymers with 55 arms did not show a liquid–solid transition in dense suspensions, but the transition could be induced by replacement of a fraction of frozen star polymers with dynamic star polymers. The same effect could be obtained if a fraction of frozen star polymers with 55 arms was replaced with frozen star polymers with 112 arms. Dense binary suspensions of frozen star polymers ...