Premium
Counterion effects in the anionic polymerization of methyl methacrylate: Mechanistic relevance to GTP
Author(s) -
Warmkessel Jeffrey,
Kim Jungsoo,
Quirk Roderic P.,
Brittain William J.
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950950103
Subject(s) - counterion , deprotonation , polymerization , methyl methacrylate , chemistry , polymer chemistry , anionic addition polymerization , living anionic polymerization , ionic polymerization , gtp' , chain transfer , polymer , organic chemistry , radical polymerization , ion , enzyme
The room temperature polymerization of methyl methacrylate (MMA) by the cesium or tetrabutylammonium salt of 9‐methylfluorenide proceeds in an uncontrolled fashion. To understand these results, we have studied the structure of the propagating chain‐ends using polymer microstructure and stopped‐flow FT‐IR spectroscopy of model compounds. Deprotonation of methyl isobutyrate with the cesium salt of 1,1,4,4‐tetraphenylbutane dianion afforded the corresponding cesium enolate (U=1645 cm −1 ). The deprotonation of methyl 2,2,4‐trimethyl‐4,6‐dicarbomethoxyhept‐6‐en‐1‐oate (the trimeric ester of MMA) was accompanied by a rapid (2–4 s) intramolecular cyclization. Comparison of group transfer polymerization (GTP) to anionic polymerization reveals that the counterion is important but probably not the sole mechanistic feature responsible for the living behavior of GTP.