Premium
Metal‐free anionic polymerization of methyl methacrylate in tetrahydrofuran using bis(triphenylphosphoranilydene)ammonium (PNP + ) as counterion
Author(s) -
Königsmann Herbert,
Jüngling Stefan,
Müller Axel H. E.
Publication year - 2000
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/1521-3927(20000701)21:11<758::aid-marc758>3.0.co;2-8
Subject(s) - polymerization , polymer chemistry , counterion , anionic addition polymerization , chemistry , methyl methacrylate , solution polymerization , living anionic polymerization , ionic polymerization , kinetics , bulk polymerization , tetrahydrofuran , precipitation polymerization , polymer , radical polymerization , organic chemistry , ion , physics , quantum mechanics , solvent
Bis(triphenylphosphoranilydene)ammonium (PNP + ) triphenylmethanide (Ph 3 C – ) is a new metal‐free initiator for the living polymerization of methyl methacrylate (MMA). The kinetics of the polymerization strongly depend on the metal counterion of the initiator precursor. When the initiator is made from the metathesis reaction of Ph 3 CK and PNPCl, the polymerization follows first‐order kinetics up to 0°C with half‐lives below 0.1 s. The propagation rate constants are much higher than those obtained with tetraphenylphosphonium (TPP + ) cations, indicating a smaller fraction of dormant ylides. When the initiator is synthesized from Ph 3 CLi, polymerization proceeds much slower and molecular weight distributions of the obtained polymers are broadened indicating that the active species are mostly lithium enolates in this case.