With ammonium persulfate (APS) as the initiator, the kinetics of methyl methacrylate (MMA) grafting polymerization onto flaky aluminum powder (Al) was studied. It was found that the experimental apparent grafting polymerization rate, R-g = KCAl0.521 x C-APS(0.429) C-MMA(0.978), was basically consistent with the theoretical result based on the theory of stable polymerization and equivalent activity, R-g = KCAl0.5 x C-APS(0.5) x C-MMA. The activation energy of grafting, homogenous, and total polymerization rate was calculated as 65.1, 35.4, and 37.5 kJ mol(-1), respectively. It could be validated that the relationship among these activation energies accorded with the theoretical result of parallel reactions. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115:3040-3044,2010