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Abstrak :
ABSTRAK
Efek inhibisi korosi dan sifat-sifat adsorpsi oleh ekstrak daun Annona Muricata (sirsak) pada baja karbon dalam larutan asam 1M HCl telah dipelajari menggunakan teknik konvensional metode berat hilang pada variasi waktu, konsentrasi dan suhu. Parameter-parameter termodinamika seperti energi aktivasi, entalpi, entropi dan perubahan energi bebas dihitung. Polarisasi elektrokimia telah dievaluasi untuk memastikan jenis inhibitor. Spektra infrared dan GCMS dilakukan untuk mengetahui senyawa ekstrak yang berperan dalam proses inhibisi. Keseluruhan hasil penelitian menunjukkan bahwa ekstrak daun sirsak dapat digunakan sebagai inhibitor korosi yang efektif pada baja karbon di lingkungan 1M HCl dengan pencapaian efisiensi 93,68% pada konsentrasi 6000 ppm selama 120 jam. Mekanisme inhibisi adalah adsorpsi fisiosorpsi berdasar rendahnya nilai entalpi dan energi bebas. Inhibisi diketahui meningkat dengan peningkatan konsentrasi dari ekstrak serta menurun dengan peningkatan suhu. Kurva polarisasi menunjukkan inhibitor ini berperilaku sebagai inhibitor campuran dengan dominan pada inhibisi katodik.

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Abstract
The corrosion inhibition effect and adsorption properties by the extract of Annona Muricata (graviola) leaves on carbon steel in hydrochloric acid were studied using convensional mass loss method at various time, concentrations and temperature. Thermodynamic parameters such as energy activation, enthalpy, entropy and change in the free energy are calculated. Electrochemical polarization was evaluated to confirm the type of inhibitor. Infra red spectra & GCMS are evaluated to reveal compounds of extract which effect the inhibition process. The entire study shows that ethanol extract of Annona Muricata leaves could serve as an effective inhibitor of the corrosion of mild steel in 1M HCl media with optimum efficiency of inhibitor up to 93,68 % for 120 hours. Mechanism of inhibition is fisiosorpsi adsorption due to low entalphy and free energy. Inhibition was found to increase with increasing concentration of the leaves extract and decrease with increasing temperature. Polarisation curves reavealed that this inhibitor act as a mixed type inhibitor with predominant in catodic inhibition.

Abstrak :
Mekanisme inhibisi korosi dari inhibitor berbahan dasar imidazoline pada baja API 5L Grade B di lingkungan NaCl 3,5% diinvestigasi dengan menggunakan metode model adsorpsi yang didapat dari hasil pengujian Tafel Polarisasi, Linier Polarisasi dan Electrochemical Impedance Spectroscopy (EIS) dengan menggunakan variasi konsentrasi 0 ppm, 50 ppm, 100 ppm, 150 ppm, 200 ppm dan 250 ppm. Senyawa imidazoline yang teradsorpsi pada permukaan logam diinvestigasi dengan menggunakan pengujian Fourier Transform InfraRed (FTIR). Hasilnya didapatkan bahwa proses adsorpsi inhibitor imidazoline terjadi secara spontan mengikuti mode adsorpsi Langmuir isoterm. Berdasarkan nilai Goads antara -16,2 kJ/mol sampai -17,5 kJ/mol menunjukkan bahwa inhibitor imidazoline menginhibisi korosi dengan cara adsorpsi fisika (interaksi elektrostatis antara muatan negatif molekul inhibitor dengan muatan positif permukaan logam) membentuk lapisan tunggal di permukaan logam sehingga dapat menghambat proses korosi. Besarnya efisiensi inhibisi inhibitor berbahan dasar imidazoline bergantung pada konsentrasi inhibitor. Efisiensi inhibisi tertinggi diperoleh pada konsentrasi imidazoline 250 ppm sebesar 72,69% berdasarkan hasil pengujian Linier polarisasi. ......Corrosion inhibition mechanism of imidazoline-based corrosion inhibitor on API 5L Grade B steel in 3.5% NaCl environment was investigated by using adsorption method from the results of tafel polarization, linier polarization resistance (LPR), and Electrochemical Impedance Spectroscopy (EIS) tests with 0 ppm, 50 ppm, 100 ppm, 150 ppm, 200 ppm and 150 ppm concentration variation. Imidazoline compounds which adsorbed on metal surface was also investigated by Fourier Transform InfraRed (FTIR) test. It was found that adsorption process of imidazoline-based inhibitor occurs spontaneously and follow the Langmuir adsorption isotherm. From the calculation of Goads (around -16,2 kJ/mol to -17,5 kJ/mol), it indicates that the inhibitor inhibited corrosion by physisorption (involving electrostatic attraction between the negative charged of inhibitor molecules and the positive charged of metal surface) to form a monolayer on the metal surface so that corrosion will be obstructed. Inhibition efficiency of imidazoline-based inhibitor was concentration dependent. The optimum inhibition efficiency is 72,69% in 250 ppm concentration of imidazoline as a result of LPR test.

Abstrak :
This research was carried out to investigate the comprehensive information on the carbon dioxide corrosion of steel by cetylamine inhibitor at various concentration......

Abstrak :
Corrosion is a degradation process of metal quality due to chemical reaction between metal and their environment. One of the methods widely used to control corrosion is using corrosion inhibitor. Imidazoline is used as an organic corrosion inhibitor because it has good adsorption characteristic, can make a protector film on carbon steel surface, and has hydrophobic sites. In this research, imidazoline derivatives from triethylenetetramine (TETA) were successfully synthesized with various fatty acid i.e. stearic (SA), oleic (OA), and linoleic acid (LNA), yielded TETA-SA, TETA-OA, TETA-LNA, respectively, using MAOS (Microwave Assisted Organic Synthesis) method with variation of reaction times. The optimum yield of TETA-SA was obtained at 9 minutes reaction time (89.12%), TETA-OA at 13 minutes (98.79%), and the optimum mass for TETA-LNA was obtained at 9 minutes (1.7023 g). The as-synthesis of TETA-SA from MAOS method had been compared with reflux and Dean Stark methods with xylene as solvent and it was obtained that the highest percentage yield came at 13 hours reaction time for both reflux (96.83%) and Dean-Stark (97.27%) methods. The as-synthesis imidazolines then were identified using thin layer chromatography (TLC), melting point test, and further characterized using UV-Vis, FTIR, ¹H-NMR, and LC-MS/MS instruments. Corrosion inhibition activity was measured by varying the concentration of all as-synthesis compounds (100, 200, 300, 400, and 500 ppm) in various concentration of NaCl (1%, 3%, and 5%) by cyclic voltammetry method using potentiostat then processed using Tafel polarization method to obtain percentage of inhibition efficiency (%IE). The results from corrosion inhibition activities, showed the highest %IE were obtained at 500 ppm of TETA-SA, TETA-OA, and TETA-LNA with %IE of 84.54%, 85.63%, and 89.26% (1% NaCl); 66.82%, 70.98%, and 75.23% (3% NaCl); and 52.30%, 54.18%, and 60.19% (5% NaCl), respectively. These results revealed that the more double bonds in hydrocarbon chain of imidazoline, the higher %IE will be produced. In line with increasing NaCl concentration in the environment, %IE will be decreased; but imidazoline derivatives still had their activities as corrosion inhibitor towards carbon steel.  Therefor, it can be suggested that imidazoline derivatives can be used as corrosion inhibitor on carbon steel in high salinity of sea water.

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Korosi adalah suatu proses penurunan kualitas logam karena adanya reaksi kimia antara logam dengan lingkungannya. Salah satu metode untuk mengendalikan korosi yaitu dengan menggunakan inhibitor korosi. Imidazolin digunakan sebagai inhibitor korosi organik karena memiliki karakter adsorpsi yang baik, dapat membentuk lapisan pelindung pada permukaan logam, dan memiliki lapisan hidrofobik. Pada penelitian ini telah berhasil disintesis tiga senyawa turunan imidazolin dari reaksi antara TETA (trietilentetramina) dengan variasi asam lemak, yaitu asam stearat (AS), oleat (AO), dan linoleat (ALN), berturut-turut yaitu TETA-AS, TETA-AO, dan TETA-ALN menggunakan metode MAOS (Microwave Assisted Organic Synthesis) dengan variasi waktu reaksi. Persen yield optimum dari senyawa TETA-AS didapatkan pada waktu reaksi 9 menit (89,12%), TETA-AO 13 menit (98,79%), dan massa opimum untuk TETA-ALN diperoleh pada menit ke 9 (1,7023 g). Hasil sintesis senyawa TETA-AS dengan metode MAOS telah dibandingkan dengan metode refluks dan Dean Stark dalam pelarut xylena dan diperoleh % yield tertinggi pada waktu reaksi 13 jam untuk refluks (96,83%) dan Dean-Stark (97,27%). Terhadap hasil reaksi dilakukan identifikasi dengan menggunakan kromatografi lapis tipis (KLT) dan uji titik leleh, selanjutnya dilakukan karakterisasi menggunakan instrumen UV-Vis, FTIR, 1H-NMR, dan LC-MS/MS. Uji aktivitas inhibisi korosi dilakukan dengan memvariasikan konsentrasi seluruh senyawa hasil sintesis (100, 200, 300, 400, dan 500 ppm) serta variasi konsentrasi NaCl (1%, 3%, dan 5%) dengan metode siklik voltametri menggunakan potensiostat yang kemudian diolah menggunakan metode polarisasi Tafel untuk memperoleh nilai persen efisiensi inhibisi (%EI). Dari hasil pengukuran, diperoleh bahwa nilai %EI tertinggi berada pada konsentrasi 500 ppm dari senyawa TETA-AS, TETA-AO, dan TETA-ALN dengan nilai %EI berturut-turut 84,54%; 85,63%; dan 89,26% (NaCl 1%); 66,82%; 70,98%; dan 75,23% (NaCl 3%); serta 52,30%; 54,18%; dan 60,19% (NaCl 5%). Hasil uji aktivitas dalam menginhibisi korosi menunjukkan bahwa semakin banyak jumlah ikatan rangkap pada rantai hidrokarbon senyawa turunan imidazolin, semakin tinggi pula nilai %EI yang dihasilkan. Seiring dengan bertambahnya konsentrasi larutan NaCl dalam lingkungan akan menurunkan nilai %EI, namun senyawa turunan imidazolin masih memiliki aktivitas sebagai inhibitor korosi pada baja karbon. Sehingga diharapkan senyawa turunan imidazolin dapat digunakan sebagai inhibitor korosi pada baja karbon dalam perairan laut dengan kadar garam yang tinggi.

Abstrak :
ABSTRAK
In order to maintain issued of environmental safe and clean, Indonesian government has been tried very hard to reduce toxicity, especially in water cooling systems by prohibiting chromate to be used.

A part from inhibitor chromate, the industries still use some inhibitors such as zinc phosphate, polyphosphonat etc, but the dangers of these inhibitors still unsolved. To anticipated of this condition, in this time has been made an advances of development of unpoisonous inhibitor called Ascorbic Acid (vitamin C).

The investigation started with behaviour of Ascorbic Acid in near neutral aqueous solution regarding corrosion of stainless steel. The experiment result indicated that inhibition of Ascorbic Acid gave effectiveness of 75 - 83 %. with intervals of 60 - 100 ppm. This effectiveness values can be said that Ascorbic Acid very promising to be used for inhibitor corrosion. Furthermore research must take place to get more information about inhibition of Ascorbic Acid, so that Ascorbic Acid can be used commercially in industries.

Abstrak :
Permasalahan korosi dalam bidang minyak dan gas, menjadi salah satu perhatian serius. Proses penanganan korosi ini dilakukan dengan dua klasifikasi metode yaitu secara fisika dan kimia. Pada penelitian ini dilakukan penanganan korosi secara kimia menggunakan 2-mercaptobenzothiazole (MBT) sebagai inhibitor korosi pada tembaga. Pengamatan dilakukan menggunakan metode berat hilang dan polarisasi ekstrapolasi Tafel dalam larutan yang mengandung ion klorida (HCl dan brine). Karakteristik film yang terbentuk diamati menggunakan spektrofotometer ATR-IR dan spektrofotometer UV Vis. Studi morfologi hasil menggunakan SEM. Hasil penelitian menunjukkan bahwa terbentuknya film Cu(II)-2-mercaptobenzothiazole pada permukaan tembaga melalui mekanisme adsorpsi isotermal Langmuir. Peningkatan konsentrasi MBT akan meningkatkan % inhibisi pada tembaga dari proses korosi, sedangkan peningkatan temperatur akan menurunkan % inhibisi korosi pada tembaga dikonsentrasi yang sama. Aplikasi penggunaan MBT dengan konsentrasi minimal 25 ppm pada temperatur 70 oC dengan waktu kontak 72 jam memberikan % inhibisi diatas 90,00 % pada brine sintetis. ...... Corrosion problems in oil and gas fields are very serious concern. Corrosion treatment process is used by two methods, physical and chemical. In this research, the corrosion treatment by chemical method with 2-mercaptobenzothiazole (MBT) as a corrosion inhibitor in copper. This research used weight loss method and polarization with extrapolation Tafel in solution which chloride ion contains (HCl and brine). Characteristic of film layer using ATR-IR spectrophotometer and UV Vis spectrophotometer. Surface morphological study was observed on SEM. The results showed that formed Cu(II)-2-mercaptobenzothiazole on copper surface through the Langmuir isothermal adsorption mechanism. Increasing of concentration MBT will improve the % inhibition of copper from the corrosion process, whereas an increase in temperature will decrease the % corrosion inhibition of copper in the same concentration. The application of MBT in the minimal concentration 25 ppm at 70 °C in 72 hours contact times gave % inhibition value more than 90.00 % in synthetic brine.

Abstrak :
Pada proses pre-commisioning jaringan pipa bawah laut diperlukan pencegahan korosi dimana laju korosi material baja API 5L grade B di dalam larutan 3,5 % NaCl teraerasi pada kondisi steady masih relatif tinggi yang dapat mencapai lebih dari 20 mpy (0,5 mm/tahun). Upaya pencegahan korosi pada saat proses hydrotest dengan media air laut dilakukan dengan penambahan inhibitor anorganik yang mengandung zat corrosion inhibitor, oxygen scavenger dan biocide sehingga diperlukan bahan organik alternatif ramah lingkungan dengan kinerja yang lebih baik. Tujuan utama dari penelitian ini adalah untuk menginvestigasi efisiensi dari penggunaan campuran ekstrak sarang semut dan sirih merah sebagai alternatif inhibitor ramah lingkungan atau bahan campuran untuk mengurangi penggunaan inhibitor anorganik pada perlindungan korosi material baja API 5L Grade B dalam lingkungan 3,5% NaCl. Kemampuan inhibisi korosi dari hasil ekstrak bahan alami diinvestigasi dengan menggunakan pengujian Tafel polarisasi dan Electrochemical Impedance Spectroscopy (EIS) serta diverifikasi dengan pengujian kehilangan berat. Kandungan senyawa aktif dalam ekstrak sarang semut dan sirih merah beserta senyawa teradsorpsi pada permukaan logam dan mekaniseme inhibisi elektrokimia diinvestigasi dengan pengujian EIS, FTIR dan model adsorpsi isoterm. Pada konsentrasi campuran green inhibitor 2ml sarang semut + 1ml sirih merah, effisiensi inhibitor dapat mencapai 73,66%. Pada penggunaan sebagai inhibitor campuran dengan inhibitor kimia pada konsentrasi campuran 1ml kimia + 2ml green inhibitor, dapat menurunkan laju korosi secara signifikan dari 0,42 mm/year menjadi 0,03 mm/year dengan efisiensi mencapai 93,15%. Inhibitor korosi tersebut berpengaruh terhadap kurva polarisasi anodik maupun katodik sehingga dapat berperan sebagai mixed inhibitor. Pengujian FTIR menunjukan adanya gugus-gugus fungsi ikatan kimia yang berkombinasi sebagai pembentuk lapisan (film forming) seperti Gugus hidroksil, karbonil, aromatik, alkane dan amina. Adsorpsi senyawa-senyawa terkandung dalam inhibitor sarang semut dan sirih merah pada permukaan logam terjadi spontan mengikuti Langmuir adsorpsi isoterm. Hasil ini sesuai dengan hipotesis awal bahwa ekstrak sarang semut dan sirih merah yang mengandung senyawa antioksidan dapat mencegah proses oksidasi pada permukaan logam sehingga akan mengurangi laju korosi. ......During pre-commissioning of subsea pipeline are require corrosion prevention since the corrosion rate of steel material of API 5L grade B in 3.5% NaCl aerated solution under steady state condition is still relatively high (can reach more than 0,5 mm/year). Method to prevent the corrosion during subsea pipeline hydrotest using seawater is generally by the addition of inorganic inhibitor containing corrosion inhibitor agent, oxygen scavenger and biocide, so that require to find out the alternative eco- friendly materials with better performance. The main objective of this study is to investigate the efficiency of the use of mixture of extract of myrmecodia pendans and piper crocatum as an alternative of eco-friendly inhibitor or a compound for reducing the use of inorganic inhibitors for corrosion protection of steel material API 5L Grade B in 3,5% NaCl Environmental. The corrosion inhibition ability of natural ingredient extraction are investigated by using tafel polarization test and electrochemical impedance spectroscopy (EIS) and verified by weight loss test. The content of the active compounds in the extract of Myrmecodia Pendans and Piper Crocatum along with adsorption compound on metal surfaces and electrochemical inhibition mekaniseme are investigated by EIS, FTIR testing and model of the Langmuir adsorption isotherm. The addition of mixed green inhibitor concentration of 2ml myrmecodia pendans and 1ml piper crocatum is resulted in approximately 73.66% inhibitor efficiency while the addition of mixed green inhibitor into chemical inhibitor with concentration of 1ml for chemical and 2ml for green inhibitor are significantly reduce the corrosion rate from 0.42 mm/year to be 0.03 mm/year with approximately 93.15% inhibitor efficiency. The green inhibitor affected the cathodic as well as the anodic polarization curves which were known as mixed corrosion inhibitor type. The type of chemical bonds on the steel surface layer was analyzed by FTIR method which indicated hydroxyl, carbonyl, aromatic, alkane and amine group. The adsorption of compounds contained in the myrmecodia pendans and piper crocatum inhibitor on a metal surface are occur spontaneously follows the Langmuir adsorption isotherm. These results are consistent with the initial hypothesis that the extract of myrmecodia pendans and piper crocatum contains antioxidant compound which can prevent the oxidation process in the metal surface thereby will reducing the corrosion rate.

Abstrak :
Korosi yang disebabkan oleh karbondioksida (CO2) pada pipa baja karbon dan peralatan di pengolahan minyak dan gas sangat umum terjadi. CO2 larut dalam air menghasilkan asam karbonat (H2CO3) yang mempunyai sifat yang lebih korosif dibanding asam klorida (HCL) pada pH yang sama. Electrochemical impedance spectroscopy dan linear polarization resistance digunakan untuk mengetahui fenomena proses yang terjadi selama proses adsorbsi inhibitor di permukaan logam. Variasi temperature dan konsentrasi dari inhibitor dilakukan untuk mengetahui kemampuan inhibisi inhibitor dan mekanisme inhibisi. Penelitian ini dilakukan pada baja karbon A106 grB di dalam lingkungan 3% NaCl. Konsentrasi inhibitor bervariasi dari 0,5,15, dan 40 ppm dan dengan variasi temperature di 40 0C dan 90 0C. Pada temperature 40 0C laju korosi menunjukan 213,9 MPY pada lingkungan tanpa penambahan inhibitor , dan akan turun drastis ke 22,4 MPY ketika 5 ppm inhibitor ditambahkan ke lingkungan, dengan effisiensi inhibisi 90%. Penambahan konsentrasi inhibitor sampai 40 ppm meningkatkan effisiensi inhibisi sampai 98%. Penambahan konsentrasi inhibitor berbasis Imidazoline dari dari 0 ppm sampai 5 ppm pada temperature 90 0C dapat menghasilkan penurunan laju korosi yang signifikan yaitu dari 173,3 MPY menjadi 31,67 MPY, dengan effisiensi inhibisi 82%. Dengan penambahan konsentrasi inhibitor sebanyak 40 ppm akan menaikan effisiensi inhibisi sampai 99,99 %. Mekanisme penghambatan laju korosi terjadi sebagai akibat terbentuknya ikatan polar (O-H dan N-H) yang berikatan dengan permukaan logam melalui proses chemisorption.

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Corrosion caused by carbon dioxide (CO2) in carbon steel pipes and equipment in oil and gas processing is very common. Water soluble CO2 produces carbonic acid (H2CO3) which has more corrosive properties than hydrochloric acid (HCL) at the same pH. Electrochemical impedance spectroscopy and linear polarization resistance are used to determine the processes that occur during the adsorbs inhibitor process on the metal surface. Variation of concentration of the inhibitor is conducted to determine the ability of inhibitor inhibition and inhibition mechanism. This research was conducted on A106 gr. B carbon steel in an environment of 3% NaCl. The inhibitor concentration varies from 0,5,15, and 40 ppm at 40 0C. At temperatures of 400C the corrosion rate shows 213.9 MPY in the environment without the addition of inhibitors, and will drop dramatically to 22.4 MPY when 5 ppm inhibitors are added to the environment. Electrochemical Impedance Spectroscopy is used to study inhibition mechanism. Increasing the concentration of Imidazoline based inhibitors from 0 ppm to 5 ppm at 90 0C can produce a significant decrease in corrosion rate from 173.3 MPY to 31.67 MPY, with 82% inhibition efficiency. With the addition of inhibitor concentrations up to 40 ppm will increase inhibition efficiency to 99,99 %. The mechanism of inhibition of corrosion rate occurs as a result of the formation of polar bonds (O-H and N-H) that bind to the metal surface through a chemisorption process.

Abstrak :
ABSTRACT
Dewasa ini, kebutuhan inhibitor korosi di Indonesia semakin meningkat seiring dengan banyaknya industri minyak dan gas bumi. Oleh karena itu, diperlukan suatu penelitian mengenai sintesis inhibitor korosi khususnya yang berbasis senyawa organik untuk menangani permasalahan tersebut. Senyawa turunan imidazolin merupakan salah satu senyawa organik yang sering digunakan sebagai inhibitor korosi pada baja karbon. Pada penelitian ini, telah berhasil disintesis senyawa turunan imidazolin yaitu EDA-AS, DETA-AS, TETA-AS, dan AEEA-AS dengan mereaksikan asam stearat (AS) dan variasi poliamina dengan menggunakan metode MAOS (Microwave Assisted Organic Synthesis). Persen yield optimum senyawa EDA-AS diperoleh pada waktu sintesis 5 menit (94,28%), DETA-AS 7 menit (89,81%), TETA-AS 9 menit (89,18%), dan AEEA-AS 3 menit (96,21%). Sintesis senyawa TETA-AS menggunakan metode Dean Stark dan refluks juga dilakukan sebagai pembanding untuk mengetahui metode yang lebih efektif dan efisien, dimana diperoleh % yield tertinggi yaitu menggunakan metode Dean Stark (97,27%), diikuti oleh metode refluks (96,83%) dan MAOS (89,81%). Seluruh senyawa hasil sintesis telah dikonfirmasi strukturnya menggunakan instrumen UV-Vis, FT-IR, 1H-NMR, dan LC-MS/MS dimana terlebih dahulu diuji kemurniannya menggunakan kromatografi lapis tipis (KLT) dan alat pengukur titik leleh. Hasil sintesis kemudian diuji aktivitasnya sebagai inhibitor korosi terhadap baja karbon dalam larutan 1% NaCl dengan memvariasikan konsentrasi imidazolin (100, 200, 300, 400, dan 500 ppm) yang kemudian diolah dengan menggunakan metode polarisasi Tafel. Nilai %EI tertinggi diperoleh pada penambahan 500 ppm senyawa EDA-AS, DETA-AS, TETA-AS, dan AEEA-AS berturut-turut sebesar 74,21%; 75,90%; 85,52%; dan 89,70%. Penelitian ini telah membuktikan bahwa dengan memvariasikan poliamina akan sangat mempengaruhi aktivitas inhibisi dimana pada senyawa AEEA-AS memiliki aktivitas inhibisi paling besar karena memiliki kelektronegatifan yang lebih besar dibandingkan senyawa lainnya. Berdasarkan data yang diperoleh pada penelitian ini, dapat disimpulkan bahwa senyawa turunan imidazolin dapat memiliki kemampuan sebagai inhibitor korosi pada baja karbon.

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ABSTRACT
Nowadays, the need of corrosion inhibitors in Indonesia is increasing because many oil and gas industries use equipment and instruments made of metal on their operational activities. Therefore, a study is needed on corrosion inhibitor synthesis, especially those derived from organic coumpunds to solve these problem. Imidazoline derivatives are one of the organic compounds that are often used as corrosion inhibitors in carbon steel. In this study, four imidazoline derivatives, i.e. (EDA-SA), (DETA-SA), (TETA-SA), dan (AEEA-SA) had been successfully synthesized by reacting Stearic Acid (SA) and various polyamine with variation of reaction time by using MAOS (Microwave Assisted Organic Synthesis) method. The optimum yield of imidazoline derivative compounds were obtained from EDA-SA at 5` (94,28%), DETA-SA at 7` (89,81%), TETA-SA at 9` (89,18%) and AEEA-SA at 3` (96,21%). The synthesis of TETA-SA compounds using the Dean Stark method and reflux was also carried out as a comparison to find out more effective and efficient methods, which obtained the highest% yield using Dean Stark method (97,27%), followed by the reflux method (96,83%) and MAOS (89,81%)). All of the synthesized compounds were identified by using thin layer chromatography (TLC) and examined their melting point. The structure of all synthesized compounds had been confirmed by using UV-Vis, FT-IR, 1H-NMR, and Liquid Chromatography-Mass Spectrometer (LC-MS). All of synthesized was tested for its activity as a corrosion inhibitor of carbon steel in 1% NaCl solution with variation of the imidazoline concentration (100, 200, 300, 400 and 500) ppm which is then processed using the Tafel polarization method. The highest %EI was obtained at 500 ppm of EDA-SA, DETA-SA, TETA-SA, and AEEA-SA with 74,21%; 75,90%; 85,52%; and 89,70%. This study has proven that varying polyamines will greatly influence inhibitory activity where the AEEA-SA compounds have the greatest inhibitory activity due to this compound having greater electronegativity than other compounds. Based on the data obtained in this study, it can be concluded that imidazoline derivative compounds can have the ability as corrosion inhibitors on carbon steel.