Novel Dinitroxide Mediating Agent for Stable Free-Radical Polymerization

Jeremy R. Lizotte, Sara G. Anderson, Timothy Edward Long*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


A novel dinitroxide mediating agent that was suitable for stable free-radical polymerization was synthesized and used in the block copolymerization of styrene and t-butyl styrene. Quantitative yields of a novel dinitroxide based on 1,6-hexamethylene diisocyanate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy were obtained. Various experimental parameters, including the nitroxide-to-initiator molar ratio, were examined, and it was determined that the polymerization was most controlled under conditions similar to those of conventional 2,2,6,6-tetramethyl-1-piperidi-nyloxy-mediated stable free-radical polymerization. Moreover, the dinitroxide mediator proved to be a viable route for the facile two-step synthesis of triblock copolymers of styrene and t-butyl styrene. However, the dinitroxide mediation process resulted in a higher than expected level of nitroxide decomposition, which resulted in polymers possessing a terminal alkoxyamine and an adjacent hydroxylamine rather than a preferred internal bisalkoxyamine. This decomposition resulted in the formation of diblock copolymer species during the triblock copolymer synthesis. Gel permeation chromatography was used to monitor the chain-end decomposition kinetics, and the determined observed rate constant (5.89 × 10 -5s-1) for decomposition agreed well with previous studies for other dinitroxide mediating agents.

Original languageEnglish
Pages (from-to)1547-1556
Number of pages10
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Issue number7
Publication statusPublished - 2004 Apr 1
Externally publishedYes


  • Block copolymers
  • Gel permeation chromatography (GPC)
  • Radical polymerization

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry


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