Mn a (kg mol Later on, this approach was further extended to copolymers consisting bromine at the main chains to see the effect of different halogens. Previous depolymerization and degradation experiments revealed the advantage of chlorine over bromine arising from leaving characteristics. Rapid abstraction of the halogens yields higher concentrations of free radicals on the polymer chain that may result in undesired radical coupling reactions to form branched structures. Therefore, P(MMA-co-MCA) degradation in diluted reaction conditions was initially employed. The GPC chromatograms of P(MMA-co-EBA) after 6 h of irradiation involving PPT, EY, and ErB are depicted in Fig. .