Polyaniline/partially phosphorylated poly(vinyl alcohol)/polyacrylate nanoparticles ((PAn/P-PVA)x/PAcy)were synthesized by encapsulation of varying amounts of PAn/P-PVA nanoparticles (x = 0.3, 0.5 or 0.7 g)with PAc (y = 4, 6 or 8 g acrylate monomers) via emulsifier-free emulsion polymerization. A monomerconversion level of 93.9% was achieved for the synthesis of the (PAn/P-PVA)0.5/PAc4nanoparticles. X-raydiffraction analysis revealed that PAc was intercalated between the PAn/P-PVA layers, whilst transmis-sion electron microscopy analysis of the different nanoparticles revealed they were spherical PAn/P-PVAagglomerates coated with PAc. Thermogravimetric analysis revealed that the thermal stability of the(PAn/P-PVA)/PAc nanoparticles decreased with increasing amounts of PAc. Cyclic voltammetry basedanalysis of the different (PAn/P-PVA)/PAc nanoparticles coated onto carbon fiber electrodes revealedthat the PAn/P-PVA nanoparticles were encapsulated sufficiently by the non-conductive PAc and that thepeak current decreased with increasing amounts of acrylate. With respect to the corrosion resistance in1.0 M sulfuric acid, steel coated with the (PAn/P-PVA)0.7/PAc8nanocomposite showed the best corrosionresistance (11.4%), but for the nanocomposites at each PAn/P-PVA loading level, the anticorrosive prop-erties increased with increasing PAc levels, presumably due to the increasing tortuosity of the diffusionpathway through the coating for any corrosion agents.