Development and Characterization of Epoxy/Banana Pseudo-Stem Nanocellulose (BPNC) Composites as Anti-Corrosion Coatings on Mild Steel

In the Philippines, bananas are one of the most exported agricultural products, with up to 6 million metric tons of annual harvest. Because of this, harvesting bananas generates waste like banana pseudo-stems. Banana pseudo-stems offer a good source of nanocellulose, and it was found that these have very similar chemical compositions to jute and sisal fibers, which are the most common sources of cellulose today. This only indicates that banana pseudo-stems could be utilized for different industrial and engineering applications. Epoxy-based nanocomposite coatings have attracted attention in industrial and engineering applications. Epoxy/banana pseudo-stem nanocellulose (Epoxy/BPNC) composites as anti-corrosive fillers were prepared by incorporating BPNC into the epoxy matrix to improve the anti-corrosion performance of epoxy coatings on mild steel surfaces. Their anti-corrosion properties were explored by the Tafel polarization technique under immersion in 3.5 wt.% NaCl solutions as corrosive medium. According to the results, it can be observed that epoxy/BPNC composite coatings significantly improve the anti-corrosion performance on mild steel surfaces with a 1.5 wt.% BPNC loading ratio as the optimized concentration. Furthermore, it can be seen that the optimized concentration of the BPNC loading ratio (1.5 wt.%) has a lower corrosion rate (CR = 2.7109 x 10-6 mm/year) compared to that of the bare mild steel (CR = 6.11190 x 10-2 mm/year). Additionally, the SEM results showed that the presence of BPNC in the epoxy matrix has a significant protective effect compared to pure epoxy alone.