Synergistic effect of activated carbon from disposed plastics and polybenzoxazine composite coating on corrosion inhibition

Abstract The fabrication of activated carbon dispersed polybenzoxazine (BXP) composite through a single step melt condensation technique is reported. Employing green strategy, activated carbon (AC) was obtained from various types of worn‐out plastics such as computer keyboard, sponge, electrical switches, and automobile tyres. Structural features of all the polymeric composites were explored using Fourier transform infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscope (FESEM) with Energy Dispersive X‐ray Analysis (EDAX). Thermal stability and hardness of the composites was analyzed by recording thermogravimetric analysis (TGA) and Rockwell hardness measurements. The results of thermal studies revealed that AC–BXP composites show higher thermal stability (301.98°C) than BXP (220.71°C). Rockwell hardness study (RHN) for ACWCKB@BXP is 71 whereas pristine BXP showed only 20. The corrosion protection ability of coated steel was examined through potentiodynamic polarization and electrochemical impedance spectroscopy analysis. From the Tafel plot, more shift in E corr value (from −0.6286 to −0.5065 V) towards positive side confirms its corrosion protection ability. Furthermore, the I corr , the corrosion rate and the corrosion protection efficiency of the ACWTYR@BXP composite are 0.83 × 10 −6 A/cm 2 , 0.0098 mm/year, and 99.54%, respectively, which inhibit the rate of corrosion to a greater extent in 3.5% NaCl solution. The current study applies principles of green chemistry like minimum number of synthesis steps, non‐usage of solvents and simply adoptable coating procedure.