Controlled/living radical polymerization: Features, developments, and perspectives

Recent mechanistic developments in the field of controlled/living radical polymerization (CRP) are reviewed. Particular emphasis is placed on structure-reactivity correlations and “rules” for catalyst selection in atom transfer radical polymerization (ATRP), for chain transfer agent selection in reversible addition-fragmentation chain transfer (RAFT) polymerization, and for the selection of an appropriate mediating agent in stable free radical polymerization (SFRP), including organic and transition metal persistent radicals. Novel methods of fine tuning initiation, activation, and deactivation processes for all techniques are discussed, including activators regenerated by electron transfer (ARGET) and initiators for continuous activator regeneration (ICAR) ATRP, whereby Cu catalyst concentrations in ATRP can be lowered to just 10 ppm. Progress made in each technique related to the synthesis of both high and low molecular weight polymers, end functional polymers, block copolymers, expanding the range of polymerizable monomers, synthesis of hybrid materials, environmental issues, and polymerization in aqueous media is thoroughly discussed and compared.