A good comprehension of the reaction kinetics during thermoplastic composite manufacturing by liquidreactive processes is crucial to limit the formation of porosities by monomer evaporation. This study focuses on the free-radical polymerization kinetics of Elium® C195E acrylic resin initiated by a mixture of 3 different organic peroxides over a wide range of synthesis temperature. As the polymerization of methyl methacrylate is chemically and diffusionally controlled, a variety of curve shapes were obtained from DSC experiments. To account for the different polymerization regimes, a new hybrid kinetic modelling approach based on mechanistic models has been introduced. Experimental observations have shown that an overall factor including initiator efficiency and termination rate constant can be expressed in terms of conversion and temperature as the contribution of two peaks related to the intensities of the Trommsdorff effect and vitrification. Promising simulation results of this overall factor using Richardstype equations were obtained over a broad range of isothermal synthesis temperature.