Theoretical Study on Corrosion Inhibition Properties of 2-Isopropyl-5-Methylphenol

Abstract

ABSTRAKTelah dilakukan pemodelan molekul terhadap sifat antikorosi senyawa 2-isopropil-5-metilfenol dan turunannya berdasarkan teori fungsional kerapatan pada tingkatan teori B3LYP/6-31G(d). Pengaruh penambahan gugus pendonor dan penarik elektron seperti NH2, SH, CHCH2, CH3, OH, CHO, COOH, F dan NO2 juga telah dipelajari. Parameter kuantum untuk senyawa anti korosi seperti energi orbital (EHOMO), potensial ionisasi (I), afinitas elektron (A) dan elektronegativitas (χ) memiliki hubungan yang linier dengan efisiensi anti korosi (IE %) senyawa turunan 2-isopropil-5-metilfenol. Gugus pendonor elektron meningkatkan nilai IE % sedangkan gugus penarik elektron menurunkan nilai IE %. Urutan kenaikan IE % adalah NO2 < CHO < COOH < SH < F < CH3 < CHCH2 < OH < NH2. Penambahan gugus pendonor elektron amina (NH2) meningkatkan IE % hingga 96,38 % dibandingkan IE % 2-isopropil-5-metilfenol murni 82,70 % sedangkan penambahan gugus penarik elektron nitro (NO2) menurunkan IE % hingga mencapai 68,66 %. Kajian teoritis dapat membantu mempercepat kajian eksperimental terhadap sifat anti korosi mencapai hasil yang maksimum. Kata kunci: DFT, inhibitor korosi, isopropil, metilfenol ABSTRACTCorrosion inhibitors of 2-isopropyl-5-methylphenol and its derivatives has been elucidated by means of density functional theory at B3LYP/6-31G(d) level of theory. Effect of electron donating and withdrawing groups such as NH2, SH, CHCH2, CH3, OH, CHO, COOH, F and NO2 on the corrosion inhibitor of 2-isopropyl-5-methylphenol derivatives also have been studied. The quantum chemical parameters such as the frontier orbital energies (EHOMO), ionization potential (I), electron affinity (A) and electronegativity (χ) are closely related to the corrosion inhibition efficiency (IE %) of 2-isopropyl-5-methylphenol derivatives. The presence of electron donating groups increase IE % values meanwhile electron with drawing groups reduce IE % values. The enhancement of IE % follows NO2 < CHO < COOH < SH < F < CH3 < CHCH2 < OH < NH2. Electron donating NH2 group gives 96.38 % of IE %, pure 2-isopropyl-5-methylphenol IE % = 82.70 %. In contrast, electron withdrawing NO2 group gives IE % only 68.66 %. This theoretical study

Optimasi Sifat Inhibitor Korosi Senyawa Thiaamida-Pirazolindol Berdasarkan Teori Fungsional Kerapatan

“…Obayes [23] melaporkan bahwa penambahan gugus substituen nitro menyebabkan penurunan efisiensi anti korosi sedangkan reduksi gugus nitro menyebabkan peningkatan efisiensi anti korosi. Hadisaputra [24,25] juga menggunakan teori fungsional kerapatan pada tingkatan teori B3LYP/6-31G(d) untuk mempelajari efisiensi anti korosi fenil-pirazolindol dan 2-isopropil-5-metilfenol serta turunannya. Hasil efisiensi anti korosi tertinggi diperoleh sebesar 83,12 % untuk senyawa fenil pirazolindol tersubstitusi amina.…”

Use of Polymer Membranes for Modeling Desulfurization in the Process of Pervaporation through Artificial Neural Network

“…With the help of theoretical calculations, eugenol corrosion perfor-mance can be studied more accurately and in a relatively short time. Several theoretical studies show that the corrosion inhibition properties of organic compound toward metal surface can be obtained by fast and accurate quantum-chemistry investigations (Cruz et al, 2004;Hadisaputra et al, 2016;Kabanda et al, 2013;Khaled and Al-Qahtani, 2009;Li et al, 1999;Liu et al, 2011;Musa et al, 2010;Obot and Obi-Egbedi, 2010). In this work, we use quantum chemical calculations to study the corrosion performance of acetyleugenol derivatives, mainly studied the effect of substituent groups on their corrosion performance.…”