The atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/CuBr as the initiating system was analyzed at 30, 40, 50 and 60 ℃ in N-methylimidazolium formate ([Hmim][HCOO])/THF mixtures. The polymerization was performed in a well-controlled manner as evidenced by kinetic study and the chain extension result. The apparent activation energy and the enthalpy of equilibrium for the preequilibrium were also investigated. Results show that Ea(app)=47.86 kJ/mol, △H0eq=25.67 kJ/mol. The atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB) / CuBr as the initiating system was analyzed at 30, 40, 50 and 60 ° C. in N-methylimidazolium formate ]) / THF mixtures. The polymerization was performed in a well-controlled manner as evidenced by kinetic study and the chain extension result. The apparent activation energy and the enthalpy of equilibrium for the preequilibrium were also investigated. Results show that Ea (app) = 47.86 kJ / mol, ΔH0eq = 25.67 kJ / mol.