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Alkoxyamine‐mediated “living” radical polymerization: MS investigation of the early stages of styrene polymerization initiated by cumyl‐TEISO
Authors:Salvacion P. Cresidio  Fawaz Aldabbagh  W. Ken Busfield  Ian D. Jenkins  San H. Thang  Clovia Zayas‐Holdsworth  Per B. Zetterlund
Abstract:A new series of 1,1,3,3‐tetraethylisoindoline‐2‐oxyl (TEISO)‐based alkoxyamines was prepared. The half‐lives for thermal dissociation indicated that the most sterically congested cumyl‐TEISO alkoxymine had the greatest potential as an initiator for the polymerization of monomers at lower temperatures. The polymerization of styrene at 110 °C gave a linear evolution of Mn with conversion in the early stages. Further evidence for the “living” nature was given by the polydispersities of the polymers that remained low (Mw/Mn = 1.13–1.27) throughout the polymerization (up to 80% conversion). No polymer was formed for the styrene system in a reasonable time below 100 °C. High‐performance liquid chromatographic/mass spectrometric investigations of the distribution of trapped oligomers containing one to nine monomer units formed at 60 °C revealed that the trapping of oligomeric cumyl–styryl radicals by TEISO is irreversible at this temperature. Methyl methacrylate polymerized with cumyl‐TEISO at 60–70 °C, although the initial high rates of polymerization soon decreased to zero at low conversions (10–15%), and the high polydispersities (Mw/Mn = 1.42–1.73) indicated significant side reactions. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1232–1241, 2001
Keywords:polymerization  living radical  nitroxide  styrene
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