A macroinitiator was prepared by copolymerization of styrene (St) with 7-methacryloyloxy-4-chloromethylcoumarone (MAOCMC). Grafting studies of coumarone with methyl methylacrylate were carried out in the presence of the macroinitiator poly(7-methacryloyloxy-4-chloromethylcoumarone-co-styrene) and with the catalyst of copper(I) bromide/2,2'-bipyridyne at 110°C. The activation energy valuations of graft copolymers acquired by Coats–Redfern, Tang and Flynn–Wall–Ozawa methods were designated to be 212.69, 214.44 and 223.57 kJ mol^–1, respectively. For the outcomes were compared with these valuation differential methods and discrepant integral were used. In terms of experiential outcomes, the reaction mechanism was a dimensional diffusion (Dn) deceleration type in the transformation range worked.