AbstractIn this review, the synthesis and characterization of various dimeric and polymeric peroxycarbamates and azocarbamates are described in detail. These functional polymers are synthesized by stepwise capping reactions of hydroxyl terminated polyethers, polyesters or poly(butadiene) first with diisocyanates, and then with hydroperoxides or various azo compounds containing functional groups. Statistics of chain extension reactions are discussed. Kinetic parameters of thermal decomposition are reported. These functional polymers are useful for preparing block copolymers containing soft and glassy segments.