POLY 250 |
| In an ongoing effort to design active and stable ATRP catalysts that can be used at low concentrations, the reactions contributing to the overall ATRP equilibrium have been studied. The performance of copper-based ATRP catalysts is related to the stability constants of the CuII and CuI complexes (βII and βI, respectively). High βII/βI ratios and halogenophilicity of the CuII complex lead to high catalytic activity. Halogenophilicity also determines the degree of polymerization control. Various electron transfer reactions such as CuI complex disproportionation and radical reduction or oxidation may occur in ATRP but can be suppressed by choosing the appropriate ligand. Rules for rational selection of ATRP catalysts for various monomer/solvent systems have been developed. The understanding of the factors determining the catalyst performance has enabled the development of novel initiation techniques, ICAR and ARGET ATRP, allowing the synthesis of high molecular weight polymers using ppm amounts of catalyst. |
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Herman Mark Scholar Award Symposium
8:00 AM-11:55 AM, Monday, August 20, 2007 Westin Boston Waterfront -- Grand Ballroom B, Oral
Division of Polymer Chemistry |