• atom transfer radical polymerization;
  • high pressure;
  • kinetics (polym.);
  • reversible-deactivated radical polymerization


Atom transfer radical polymerization (ATRP) rate for methyl methacrylate (MMA) in acetonitrile solution has been measured up to 2500 bar. The increase in rate, by up to two orders of magnitude for the CuBr/Me6TREN system, is not compromised by an increase in dispersity. Activation–deactivation equilibrium constants were measured for MMA, KATRP, and for two monomer-free model systems, KEBiB, and KPMMABr, with Me6TREN, TPMA, PMDETA, and HMTETA being the ligands. KATRP and KEBiB agree within one order of magnitude for Me6TREN and TPMA, but differ by about two orders of magnitude for PMDETA and HMTETA, whereas KATRP and KPMMABr are close to each other for PMDETA and HMTETA. The observations indicate an important role of back-strain effects in ATRP of MMA.