Synthesis of poly(styrene) star polymers grown from sucrose, glucose, and cyclodextrin cores via living radical polymerization mediated by a half-metallocene iron carbonyl complex

Poly(styrene) stars with 5, 8, and 18 arms were synthesized using living radical polymerization from iodinated glucose, sucrose, and cyclodextrin initiator cores, respectively. The polymerization system comprised of a half-metallocene iron carbonyl complex coupled with titanium(IV) isopropoxide. The reaction kinetics and the molecular weight development were consistent with a living/controlled radical polymerization mechanism. Poly(styrene) stars with a very narrow molecular weight distribution were obtained. Molecular weight analysis by gel permeation chromatography and NMR confirmed that the star structure was consistent with theoretical predictions. The star structure of the polymers was further verified by hydrolysis of the cores to retrieve the polystyrene arms, followed by molecular weight analysis.