LIVING RADICAL POLYMERIZATION OF METHYLSTYRENES BY A STABLE NITROXYL RADICAL, AND STABILITY OF THE AMINOXY CHAIN-END

Authors
Citation
E. Yoshida et T. Fujii, LIVING RADICAL POLYMERIZATION OF METHYLSTYRENES BY A STABLE NITROXYL RADICAL, AND STABILITY OF THE AMINOXY CHAIN-END, Journal of polymer science. Part A, Polymer chemistry, 36(2), 1998, pp. 269-276
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Polymer Sciences
ISSN journal
0887-624X
Volume
36
Issue
2
Year of publication
1998
Pages
269 - 276
Database
ISI
SICI code
0887-624X(1998)36:2<269:LRPOMB>2.0.ZU;2-U
Abstract
Radical polymerization of 2-, 3-, and 4-methylstyrenes (MeSts) was inv estigated with benzoyl peroxide (BPO) as an initiator, in the presence of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO). The polym erization was performed in bulk for 3.5 h at 95 degrees C, and then co ntinued for a defined time at 125 degrees C, to give the corresponding poly(MeSt)s with narrow polydispersity in high yield. It was found th at the polymerization proceeded in accordance with a living mechanism, because the molecular weight of the resulting polymers was proportion al to the conversion, and to the reciprocal of the initial concentrati on of MTEMPO. It was found that steric hindrance between the methyl gr oup of 2-MeSt, and the tetramethyl ones of MTEMPO, significantly contr ibuted to the rate of polymerization, and to the stability of the grow ing polymer chain end. The stability decreased in the order of 2- > 3- > 4-MeSt, by occurrence of decomposition, which was caused by disprop ortionation of the growing chain end. However, the steric hindrance ha d no effect on the tacticity of the resulting polymer. (C) 1998 John W iley & Sons, Inc.