The aqueous emulsifier-free emulsion polymerization of methyl methacrylate (MMA) was studied under the catalytic effect of a prepared complex, [Cu(NH3)(4)]SO4, with various initiators like potassium peroxodisulphate (KPS), potassium monopersulphate (KMPS) and ammonium persulphate (APS). The apparent activation energies E-a were found to be 36.52 (KMPS), 40.47 (KPS) and 31.9 kJ/mol (APS). The activation energies of initiator decomposition E-d were found to be, 31.04, 38.93 and 21.79 kJ/mol for KMPS, KPS and APS, respectively. The emulsion polymer (PMMA) latex was characterized through the determination of the size and morphology by scanning electron microscopy (SEM), FTIR spectroscopy, the average molecular weight by GPC and viscosity methods. The surface of the polymer latex was found to be somewhat 'crumpled'. From the kinetic results, the rates of polymerization, R, at 50 C were determined.