W. Schubert, F. Bandermann
Sep 1, 1989
Citations
1
Influential Citations
20
Citations
Journal
Macromolecular Chemistry and Physics
Abstract
Results of group transfer polymerization (GTP) of methyl acrylate (MA) in acetonitrile with 1-methoxy-1-propenyloxytrimethylsilane (MTP) as initiator and tris(dimethylamino)sulfonium difluorotrimethylsilicate, tris(piperidino)sulfonium difluorotrimethylsilicate, tris(dimethylamino)sulfonium bifluoride, tris(piperidine)sulfonium bifluoride, tetrabutylammonium fluoride trihydrate and tetraethylammonium cyanide as catalysts are presented. Difluorotrimethylsilicate-and bifluoride-derived catalysts are more active in GTP of MA than fluoride- and cyanide-derived ones, and lead to higher but in no case complete conversion. Polymers with number-average molecular weights up to 10000 and dispersion indices as low as Mw/Mn = 1,3 can be prepared. Molecular weight control is poor and not possible without calibration of reaction conditions, since all catalysts activate side reactions of MA (to low-molecular-weight compounds and oligomers), of MTP, and (as is assumed) also of growing chains with the solvent acetonitrile under termination. Furthermore, catalysts containing fluoride and cyanide anions initiate an anionic polymerization of MA, accompanying GTP to an appreciable extent.