The mechanism of chain activation/deactivation in RAFT is shown in Scheme 1. The reactions associated with RAFT equilibria are in addition to those (i.e., initiation, propagation and termination) that occur during conventional radical polymerization. In an ideal RAFT process, the RAFT agent should behave as a transfer agent. Termination is not suppressed by the RAFT process. Retention of the thiocarbonylthio groups in the polymeric product is responsible for the living character of RAFT polymerization and renders the process suitable for synthesizing block copolymers and end functional polymers. Removal or transformation of the thiocarbonylthio group may be required for some applications. A number of methods to accomplish the end group removal have been devised and can be readily incorporated into polymer syntheses.10, 12-16 - See more at: http://www.sigmaaldrich.com/technical-documents/articles/material-matters/reversible-addition.html#sthash.qRZ4OvCy.dpuf