An "endless" route to cyclic polymers

The team lead by Professor Robert Grubbs at CalTech developed a novel synthetic route in which the ends of growing polymer chains remain attached to a metal complex throughout the entire polymerization process, which eliminates the need for linear polymeric precursors and high dilution. A GPC system consisting DAWN EOS and Optilab detectors played crucial roles in providing strong physical evidence for circularity of the polymers synthesized. The DAWN detector was used not only for molar mass determination, but also to find that the ratio of mean square radii of cyclic and linear polymers was approximately 0.5 over a wide range of molar masses, as predicted by theory.

Bielawski, C. W.; Benitez, D.; Grubbs, R. H. Science  2002, 297, 2041-2044. DOI: 10.1126/science.1075401