Radical polymerization with reversible deactivation of active species
Polimery 2000, No 11-12, 741
SummaryThe living polymerization discovered by M. Szwarc (in ionic polymerization) opened new vistas and systems leading to living polymers are now prepared in growing numbers. Certain systems, especially ones undergoing radical polymerization, were found to produce, in spite of the termination reaction, living polymers endowed with predetermined molecular weights and narrow MWD. Such systems include those in which active species remain at equilibrium with dormant species produced by a fast and totally reversible reaction which process is on the top of a slow irreversible reaction of termination (eqns. 2, 3). First trials to produce such processes in radical polymerization date back to the 1980s, but only recently systems were developed which fully meet all the requirements. The nitroxide mediated radical polymerization (e.g., TEMPO) (Figs. 2, 3; eqns. 5 and 7) and the atom transfer radical polymerization (ATRP, eqns. 8–10) are the processes most extensively studied. Fundamental features of these processes are reviewed, their limitations are discussed, and MALDI TOF applications are described to study the ATRP polymerization of acrylates (Fig. 4).