6533b82dfe1ef96bd1290b65
RESEARCH PRODUCT
Metal-free anionic polymerization of methyl methacrylate in tetrahydrofuran using bis(triphenylphosphoranilydene)ammonium (PNP+) as counterion
Stefan JünglingHerbert KönigsmannAxel H. E. Müllersubject
chemistry.chemical_classificationPolymers and PlasticsOrganic ChemistryInorganic chemistrySolution polymerizationchemistry.chemical_compoundAnionic addition polymerizationchemistryPolymerizationPolymer chemistryMaterials ChemistryLiving polymerizationCounterionMethyl methacrylateIonic polymerizationTetrahydrofurandescription
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 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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2000-07-01 |