The electrochemical polymerization of the monomer sulfanilamide (SAM) in an aqueous solution at room temperature produces polysulfanilamide (PSAM). The Fourier Transform Infrared spectroscopy (FTIR) was used to investigate the properties of the prepared polymer layer that generated on the stainless steel (St.S) surface (working electrode) and Atomic Force Microscope (AFM) was used to characterize the morphology, topology, and detailed surface structure of polymer layer that generated on the surface. The corrosion behavior of uncoated and coated St.S were evaluated by using the electrochemical polarization method in a 0.2 M HCl solution and a temperature range of 293–323 K, the anticorrosion action of the polymer coating on stainless steel was investigated. For the corrosion of St.S, kinetic and thermodynamic activation parameters were estimated. The effect of nanomaterials was investigated by adding them to a monomer solution to improve the anticorrosion performance of polymeric films. Graphene and nano-ZnO were used as nanomaterials in this investigation. The protection efficiency of PSAM increases with the addition of nanomaterials (Graphene and nano zinc oxide) to the monomer solution, particularly graphene, and decreases with increasing temperature (293–323 K). The values of apparent activation energies increase with the addition of different nanomaterials to the coating.