We then explored the oxidative degradation of the copolymers and tested the oxone degradation conditions that were reported by Roth. It has to be noted that similar oxidative degradation conditions were also reported by Destarac and coworkers with bleach on PVAc. In both cases, the oxidants were placed in water solutions. When the copolymer is watersoluble, the degradation was very rapid 37 and when PVAc was tested due certainly to its hydrophobic nature, weeks were necessary to observe degradation. We started with oxone degradation conditions and monitored the evolution of Mn versus conversion for one day. We did not observe any degradation whatever the copolymer used. To speed-up the degradation, we then moved from water-soluble oxidant to organo-soluble oxidant and selected meta-chloroperbenzoic acid (mCPBA). Both PS and PIBA copolymers were efficiently degraded at room temperature for 17 hours in a solution of THF containing 2.5 mol% of mCPBA. These new degradation conditions present the advantage to selectively degrade thioester moieties without using a strong base that could lead to side-reactions. To increase the differences between the virgin and degraded materials, we tried to increase the molecular weight of the polymers by preparing them at higher temperature. Our calculations on kp/ktr values showed a low temperature dependence (see ESI Table for details) and we could thus expect to have the same reactivity and therefore random copolymers with these conditions. We thus performed the copolymerization of POT with styrene and IBA at 120 ºC without initiator and with 2.5 mol% of POT.