IMIT   21220
INSTITUTO DE MODELADO E INNOVACION TECNOLOGICA
Unidad Ejecutora - UE
artículos
Título:
In-situ nitroxide mediated polymerization of styrene promoted by the N-tert-butyl-á-isopropylnitrone/BPO pair: ESR investigations
Autor/es:
CHRISTOPHE DETREMBLEUR; JEAN-LOUIS CLÉMENT; VALÉRIE SCIANNAMÉA; CHRISTINE JEROME; JEAN-MARIE CATALA; DIDIER GIGMES; LAURENT AUTISSIER; EDITH BOTEK; NATALIA ZARYCZ; BENOÎT CHAMPAGNE
Revista:
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
Editorial:
JOHN WILEY & SONS INC
Referencias:
Lugar: New York; Año: 2013 vol. 51 p. 1786 - 1795
ISSN:
0887-624X
Resumen:
The styrene polymerization initiated by benzoyl peroxide (BPO) in the presence of N-tert-butyl-á-isopropylnitrone as nitroxide precursor is well-controlled provided that a pre reaction  between the nitrone and BPO is carried out in suitable conditions prior to polymerization at a  higher temperature. Electron Spin Resonance (ESR) spectroscopy was implemented to probe  the nitroxides formed during both steps; i.e. the pre-reaction and polymerization, and to get crucial information regarding the structure of the  nitroxides responsible for the  polymerization control. ESR studies combined with first principles calculations have evidenced that nitroxides observed during the pre-reaction in the presence of styrene and during the polymerization steps consist of a mixture of two macronitroxides. One is formed by the addition of a growing polystyrene chain to the nitrone as would be expected. However, the second one results from the addition of a polystyrene chain to  tert-butyl nitroso that is  in-situ formed presumably by decomposition of the first macronitroxide type.