[ABSTRAK
Penelitian pemanfaatan ekstrak tumbuh-tumbuhan sebagai inhibitor korosibelakangan ini semakin meningkat seiring dengan meningkatnya permintaanpenggunaan bahan-bahan kimia yang ramah lingkungan. Pemanfaatan ekstraktumbuh-tumbuhan sebagai inhibitor korosi menjadi penting mengingatkarakteristiknya ramah lingkungan (green inhibitor), mudah ketersediaannnya,sumberdaya yang melimpah dan dapat diperbaharui, prosedur produksi yangsederhana, dan biaya produksi yang cukup kompetitif. Dalam penelitian inidilakukan pengujian eksperimental efek sinergis jenis inhhibitor baru yaituekstrak ubi ungu (Ipomoea batatas L.) yang memiliki kandungan utamaantosianin dengan inhibitor komersial berbasis amine (aniline) dan denganinhibitor asam askorbat.Penelitian bertujuan untuk menganalisis laju kororsi dan efisiensi inhibisikorosi logam baja (API 5L) di dalam lingkungan air terproduksi menggunakaninhibitor campuran ekstrak ubi ungu dan inhibitor komersial berbasis amine(aniline). Selain itu dilakukan pula analisis laju korosi, efisiensi inhibisi,mekanisme proteksi dan model lapisan inhibisi korosi logam baja (API 5L) didalam lingkungan 3,5% NaCl menggunakan inhibitor campuran ekstrak ubi ungudan asam askorbat.Metode pengukuran laju korosi dan efisiensi inhibisi dilakukanmenggunakan elektrokimia kurva polarisasi. Mekanisme korosi diteliti denganmenggunakan metode Electrochemical Impedance Spectroscopy (EIS). Untukmenganalisis model lapisan inhibisi dilakukan dengan menggunakan metodeFourier Transform Infra Red (FTIR) spectroscopy.Hasil penelitian menunjukan bahwa pencampuran ekstrak ubi ungumemiliki kemampuan sinergis dengan inhibitor komersial berbasis amine (aniline)pada fraksi volume ekstrak ubi ungu sebesar 25% dengan menghasilkan efisiensiinhibisi sebesar 82,14%. Sebagai pembanding, pada sistem yang samapenggunaan esktrak ubi ungu saja menghasilkan efisiensi inhibisi 68,30%,sedangkan penggunaan inhibitor komersial berbasis amine (aniline) sajamenghasilkan efisiensi inhibisi 74,88%.Penambahan volume ekstrak ubi ungu dari 1 mL hingga 4 mL kedalaminhibitor asam askorbat 10-4 M meningkatkan efisiensi inhibisi korosi logam baja(API 5L) dalam larutan 3,5% NaCl dari efisiensi inhibisi sebesar 23,37% menjadi57,52%. Campuran inhibitor korosi tersebut berpengaruh terhadap kurvapolarisasi anodik maupun katodik sehingga dapat berperan sebagai mixedinhibitor. Pengujian EIS menunjukan proses korosi dikontrol oleh mekanismepasivasi yang ditunjukan oleh adanya peningkatan tahanan permukaan korosi.Pada lapisan permukaan terjadi proses adsorpsi dan pembentukan kelatorgano (flavonoid) logam dimana ekstrak ubi ungu dengan kandungan utamaantosianin berperan sebagai pembentuk metal-chelated. Pembentukan kelatekstrak ubi ungu-Fe-asam askorbat terjadi pada gugus hidroksil dan karbonil.Lokasi terjadinya ligan kelat ekstrak ubi ungu dengan kandungan utma antosianinterjadi pada ikatan 3?, 4? Dihydroxy cincin B atau 3-Hydroxy 4-Carbonyl cincin C;

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ABSTRACT
Research of utilization of plant extracts as a corrosion inhibitor recentlyincreased along with the increasing demand for the use of chemicals that areenvironmentally friendly. Utilization of plant extracts as a corrosion inhibitorbecomes important given the characteristics of environmentally friendly (greeninhibitor), easy availability, resources are abundant and renewable, the productionprocedure is simple, and the production costs are quite competitive. In thisresearch, experimental testing of the synergistic effects of new types inhibitor ieextract purple potato (Ipomoea batatas L.) which has the main content ofanthocyanin with commercial inhibitor-based amine (aniline) and with ascorbicacid inhibitors.The study aims to analyze the rate of corrosion and metal corrosioninhibition efficiency of steel (API 5L) in the produced water environment using amixed inhibitor purple sweet potato extract and commercial-based inhibitors ofamine (aniline). In addition, the corrosion rate analysis was also performed,inhibition efficiency, protection mechanisms and models of metal corrosioninhibition layer steel (API 5L) in the neighborhood of 3.5% NaCl using a mixedinhibitor purple sweet potato extract and ascorbic acid.Method of measuring the rate of corrosion and inhibition efficiency wasperformed using electrochemical polarization curves. Corrosion mechanismsinvestigated by Electrochemical Impedance Spectroscopy (EIS). To analyze themodel layer of inhibition were calculated using Fourier Transform Infra Red(FTIR) spectroscopy.The results showed that mixing purple sweetpotato extract has the abilityto synergistically with commercial inhibitor-based amine (aniline) in purplesweetpotato extract volume fraction of 25% with a yield of 82.14% inhibitionefficiency. For comparison, the same system using purple sweet potato extractonly produce inhibition efficiency of 68.30%, while the use of commercial-basedinhibitors of amine (aniline) alone resulted in inhibition efficiency of 74.88%.The addition of purple sweet potato extract volume of 1 mL to 4 mL intoascorbic acid inhibitors 10-4 M improving steel metal corrosion inhibitionefficiency (API 5L) in a solution of 3.5% NaCl of inhibition efficiency of 23.37%to 57.52%. The corrosion inhibitor mixture affect the anodic and cathodicpolarization curves so that it can act as a mixed inhibitor. Testing EIS shows thecorrosion process is controlled by the passivation mechanism indicated by anincrease in the surface resistance of corrosion.On the surface layer of a process of adsorption and formation of organochelates (flavonoids) in which the metal purple sweet potato extract with the maincontent of anthocyanins act as forming metal-chelated. Location of the chelatingligand purple sweet potato extract with the main content of anthocyanins occur inbond 3 ', 4' dihydroxy ring B or 3-Hydroxy 4-Carbonyl ring C.;Research of utilization of plant extracts as a corrosion inhibitor recentlyincreased along with the increasing demand for the use of chemicals that areenvironmentally friendly. Utilization of plant extracts as a corrosion inhibitorbecomes important given the characteristics of environmentally friendly (greeninhibitor), easy availability, resources are abundant and renewable, the productionprocedure is simple, and the production costs are quite competitive. In thisresearch, experimental testing of the synergistic effects of new types inhibitor ieextract purple potato (Ipomoea batatas L.) which has the main content ofanthocyanin with commercial inhibitor-based amine (aniline) and with ascorbicacid inhibitors.The study aims to analyze the rate of corrosion and metal corrosioninhibition efficiency of steel (API 5L) in the produced water environment using amixed inhibitor purple sweet potato extract and commercial-based inhibitors ofamine (aniline). In addition, the corrosion rate analysis was also performed,inhibition efficiency, protection mechanisms and models of metal corrosioninhibition layer steel (API 5L) in the neighborhood of 3.5% NaCl using a mixedinhibitor purple sweet potato extract and ascorbic acid.Method of measuring the rate of corrosion and inhibition efficiency wasperformed using electrochemical polarization curves. Corrosion mechanismsinvestigated by Electrochemical Impedance Spectroscopy (EIS). To analyze themodel layer of inhibition were calculated using Fourier Transform Infra Red(FTIR) spectroscopy.The results showed that mixing purple sweetpotato extract has the abilityto synergistically with commercial inhibitor-based amine (aniline) in purplesweetpotato extract volume fraction of 25% with a yield of 82.14% inhibitionefficiency. For comparison, the same system using purple sweet potato extractonly produce inhibition efficiency of 68.30%, while the use of commercial-basedinhibitors of amine (aniline) alone resulted in inhibition efficiency of 74.88%.The addition of purple sweet potato extract volume of 1 mL to 4 mL intoascorbic acid inhibitors 10-4 M improving steel metal corrosion inhibitionefficiency (API 5L) in a solution of 3.5% NaCl of inhibition efficiency of 23.37%to 57.52%. The corrosion inhibitor mixture affect the anodic and cathodicpolarization curves so that it can act as a mixed inhibitor. Testing EIS shows thecorrosion process is controlled by the passivation mechanism indicated by anincrease in the surface resistance of corrosion.On the surface layer of a process of adsorption and formation of organochelates (flavonoids) in which the metal purple sweet potato extract with the maincontent of anthocyanins act as forming metal-chelated. Location of the chelatingligand purple sweet potato extract with the main content of anthocyanins occur inbond 3 ', 4' dihydroxy ring B or 3-Hydroxy 4-Carbonyl ring C., Research of utilization of plant extracts as a corrosion inhibitor recentlyincreased along with the increasing demand for the use of chemicals that areenvironmentally friendly. Utilization of plant extracts as a corrosion inhibitorbecomes important given the characteristics of environmentally friendly (greeninhibitor), easy availability, resources are abundant and renewable, the productionprocedure is simple, and the production costs are quite competitive. In thisresearch, experimental testing of the synergistic effects of new types inhibitor ieextract purple potato (Ipomoea batatas L.) which has the main content ofanthocyanin with commercial inhibitor-based amine (aniline) and with ascorbicacid inhibitors.The study aims to analyze the rate of corrosion and metal corrosioninhibition efficiency of steel (API 5L) in the produced water environment using amixed inhibitor purple sweet potato extract and commercial-based inhibitors ofamine (aniline). In addition, the corrosion rate analysis was also performed,inhibition efficiency, protection mechanisms and models of metal corrosioninhibition layer steel (API 5L) in the neighborhood of 3.5% NaCl using a mixedinhibitor purple sweet potato extract and ascorbic acid.Method of measuring the rate of corrosion and inhibition efficiency wasperformed using electrochemical polarization curves. Corrosion mechanismsinvestigated by Electrochemical Impedance Spectroscopy (EIS). To analyze themodel layer of inhibition were calculated using Fourier Transform Infra Red(FTIR) spectroscopy.The results showed that mixing purple sweetpotato extract has the abilityto synergistically with commercial inhibitor-based amine (aniline) in purplesweetpotato extract volume fraction of 25% with a yield of 82.14% inhibitionefficiency. For comparison, the same system using purple sweet potato extractonly produce inhibition efficiency of 68.30%, while the use of commercial-basedinhibitors of amine (aniline) alone resulted in inhibition efficiency of 74.88%.The addition of purple sweet potato extract volume of 1 mL to 4 mL intoascorbic acid inhibitors 10-4 M improving steel metal corrosion inhibitionefficiency (API 5L) in a solution of 3.5% NaCl of inhibition efficiency of 23.37%to 57.52%. The corrosion inhibitor mixture affect the anodic and cathodicpolarization curves so that it can act as a mixed inhibitor. Testing EIS shows thecorrosion process is controlled by the passivation mechanism indicated by anincrease in the surface resistance of corrosion.On the surface layer of a process of adsorption and formation of organochelates (flavonoids) in which the metal purple sweet potato extract with the maincontent of anthocyanins act as forming metal-chelated. Location of the chelatingligand purple sweet potato extract with the main content of anthocyanins occur inbond 3 ', 4' dihydroxy ring B or 3-Hydroxy 4-Carbonyl ring C.]