Self-healing corrosion inhibition coatings with pH-responsive activity by incorporation of nano cellulose in two pack epoxy polyamide system

Benzotriazole loaded Cellulose reinforced 2 k polyamide coating system was developed to check the Corrosion inhibition performance of mild steel in 3.5 wt% nacl solution. Self-healing coatings were prepared utilizing cellulose nano fiber as a carrier for the Benzotriazole (BTA) with different loadings of 2, 4 and 6 wt%. Cellulose consists of hydroxyl groups and has sulphate and half ester groups on its surface that are acquired during Sulphuric acid hydrolysis of delignified sawdust. These hydroxyl and sulphate groups are negatively charged and provides anions to develop patina on the site of damaged coatings of mild steel for providing corrosion protection. TEM images confirmed the extracted cellulose nano fibres having cylindrical hallow shape with an average length of 176 nm and a lumen of 23 nm in size. The Electrochemical Impedance Spectroscopy (EIS) following 120 h of immersion proved that corrosion rate was decreased for BTA stacked cellulose reinforced coatings when compared to coatings without reinforcement. While Potentio dynamic examinations shows decrease in current density with increase in corrosion potential (Ecorr) for bare, standard, and for different compositions of CNB. It was also observed that the decrease in corrosion rate with respect to weight loss by reinforcement of encapsulated BTA in cellulose nano fibers implies better corrosion inhibition when compared to Bare and standard coatings of mild steel. (c) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Innovations in Clean Energy Technologies.

Automated summary

A Benzotriazole loaded Cellulose reinforced 2k polyamide coating system was developed for the corrosion inhibition of mild steel in sodium chloride solution. The study showed that the reinforcement of cellulose with encapsulated BTA can decrease corrosion rate and provide better corrosion protection, attributed to the negative charge of cellulose facilitating the formation of a patina on damaged surfaces.