Synthesis and characterization of PAni/SBR composite as corrosion prevention coating for carbon steel substrates

Corrosion results from the electrochemical interaction of materials, mostly metals, with their surrounding environment, promoting their premature deterioration. This situation has led to the development of several corrosion protection systems. However, most of them consist of coatings involving high toxicity and environmental danger.
Conducting polymers, such as polyaniline (PAni), represent an alternative approach aiming at an effective risk free corrosion inhibition. Previous studies have demonstrated that their properties induce steel to a passive state. In addition, conducting polymers are known for being biocompatible, which make them an important choice to avoid environmental and health hazards as well. However, these polymers show poor mechanical properties and weak adherence to carbon steel substrates.

Previous research works introduce the efforts to combine conducting polymers with other polymeric materials, demonstrating that it is possible to increase the stability and processability of conducting polymers by incorporating them to an elastomeric matrix, without significant diminishing of their pristine behavior.

This study is particularly focused on chemically synthesized polyaniline (PAni) by monomer oxidation and the attempt to enhance its adherence to carbon steel by mixing with styrene butadiene rubber (SBR) elastomer. This work will present the morphological and electrochemical characterization of the PAni/SBR composite by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Cyclic Voltammetry (CV). These techniques were used to evaluate the effect of SBR proportion in the mixture and the use of two different synthesis routes of PAni on the morphology and performance of the proposed material.