Synthesis and Characterization of 3-(2-hidroxy benzylidene)pentane-2,4-dione as Corrosion Inhibitor for Carbon Steel in NaCl 1% Solution (w/v)

• Main Author: Tri Lestari, Hanna
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/32263
• Institution: Institut Teknologi Bandung

Carbon steel is the material used widely in industries such as petroleum refining, fertilizer plant, water treatment, etc. However, the utilization of carbon steel is commonly facing the main problem, corrosion phenomenon. The corrosion rate of carbon steel could be reduced through the corrosion inhibitor injection method. In this research, 3-(2-hidroxybenzylidene)pentane-2,4-dione is synthesized and examined as corrosion inhibitor for carbon steel in 1% NaCl solution. This compound was synthesized by reacting salicyladehyde and acetylacetone using microwave radiation (Microwave Assisted Organic Synthesis/MAOS) at optimum temperature, 47,7 oC for 310 s with 80 watt radiation. Characterizations of 3-(2-hidroxybenzylidene)pentane-2,4-dione are Fourier Transform Infrared Spectroscopy (FTIR) measured using KBr pellet method, Nuclear Magnetic Resonance (NMR) using 1H-NMR and 13C-NMR, and Mass Spectroscopy (MS) using HRMS TOF MS ES+. This compound was obtained as dark green solids yielded 89%. The characterizations indicated the 3-(2-hidroxybenzylidene)pentane-2,4-dione compound had been successfully synthesized. Corrosion inhibition performance of 3-(2-hidroxybenzylidene)pentane-2,4-dione is examined by corrosion wheel test and electrochemical (Electrochemical Impedance Spectroscopy/EIS and Tafel) method within variation of temperature (25 oC, 45 oC, and 65 oC ) and inhibitor concentration (10, 20, 50, and 100 ppm) in 1% NaCl solution. The highest inhibition efficiency is 46,24%, obtained at 65 oC in 20 ppm of corrosion inhibitor by corrosion wheel test method, and 33,26% also obtained at 25 oC in 20 ppm by EIS method, and 64,44% obtained by Tafel polarization method at 25 oC in 100 ppm of corrosion inhibitor. Type of corrosion inhibitor of 3-(2-hidroxybenzylidene)pentane-2,4-dione determined by Tafel polarization method results ohmic/mixed inhibitor. Langmuir adsorption isotherm fitting showed 3-(2-hidroxybenzylidene)pentane-2,4-dione has half-physisorption mechanism.