Enhancing the Adhesion of Polyaniline on Steel Substrates Without a Binding Agent: Evaluated by ASTM D 3359 Tape Test and Sodium Chloride (NaCl) Exposure

This study presents a method for enhancing the adhesion of chemically synthesized polyaniline on steel substrates without the need for a binding agent. Hydrochloric acid (HCl) was used in the synthesis of polyaniline. The experiment details the in situ chemical synthesis of polyaniline and its application as a coating on steel surfaces using an air spray technique. Pre-surface treatment, including cleaning and sanding, was performed on the steel substrates prior to coating. Following the application of the polyaniline coating, heat treatment was applied, where the coating was heated to 350 °F for 3 h after it was fully dried. The adhesion properties of the coating were evaluated using the ASTM D 3359 adhesive tape test, along with short- and long-term exposure to 3.5% sodium chloride (NaCl) solution. Additional analysis, including SEM, XPS, XRD, and coating thickness measurements, demonstrates the effectiveness of polyaniline in enhancing adhesion on steel substrates.