Storage time evaluation of a residue from wine industry as a microencapsulated corrosion inhibitor for 1 M HCl

The effect of a residue from wine industry was investigated as a corrosion inhibitor for API P110 steel in hydrochloric acid. The extract was characterized using Fourier-transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (H-1 NMR) and chromatography. The influence of temperature (303-333 K) and grape peel extract concentration were studied using gravimetric and electrochemical experiments. The coupon surfaces were evaluated using microscopy techniques, FTIR-ATR and the contact angle. The by-product exhibited high weight loss efficiencies at 303 K with 4.0 g/L of the extract (83.81%) even after storage. The inhibition increased with the addition of an inorganic enhancer, indicating a synergistic effect between the active compounds and maximum efficiency of 94.48%. Polarization tests indicated that the inhibitor adsorbs on anodic and cathodic regions. The surface characterization techniques confirmed the formation of an organic film and a less attacked surface was observed for the inhibited system.