LawsonialnermisExtract Enhances Performance of Corrosion Protection of Coated Mild Steel in Seawater

Abstract

Abstract. The investigation of coating incorporated with various percentages of henna has been conducted by means of weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy method. Mild steel has been studied at ambient temperature and 50°C in order to examine the effect of temperature. The potentiodynamic polarization measurements indicate that henna extract acts as a mixed inhibitor while the corrosion rate (CR) value decreases as the current density (I corr ) decreases in the presence of 10% henna extract for both temperatures. Surface and protective film analysis have been carried out using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM).The inhibition activity is mainly correlated with the major active functional groups of lawsone. The main components can be found in lawsone structures are phenols O-H, carboxylic acid C=O and alkenes C=C. The morphology of the uninhibited sample showsa rough surface of mild steel as a result of corrosion process and severe damage can be seen. In the presence of henna, a smooth surface of mild steel anda uniform deposition of henna were observed.

Evaluating the performance of Andrographis paniculata leaves extract as additive for corrosion protection of stainless steel 316L in seawater

“…The paint selected is KTH 1K Alkyd due to the previous study showed it is suitable and workable for the incorporation of natural plant extract although the paint itself is actually made for the application on mild steel. General thinner is chosen since it is readily available and possesses similar criteria for the formulation in the previous research [29]. Three types of coating are produced based on different Kalmegh extract concentration as and the volume of extract solution was calculated based on Equation 1:…”

Analisis gugus fungsi, distribusi, dan ukuran partikel tinta stempel dari ekstrak gambir (Uncaria gambir Roxb) dengan senyawa pengomplek NaOH dan Al2(SO4)3

“…Indek polidispersitas merupakan ukuran lebarnya distribusi ukuran partikel. Nilai sumbu y pada grafik menunjukkan banyaknya partikel yang terukur pada alat PSA dan sumbu x menunjukkan rentang ukuran dari sampel yang diuji (Husni and Puspitaningrum, 2017 mengindikasikan adanya vibrasi C=C pada cincin aromatik (Hajar et al, 2016). Daerah bilangan gelombang 1284,18 cm -1 mengindikasikan adanya vibrasi C-O-C, merupakan karakteristik cincin heteroatom pada tanin.…”

“…Spektra seluruh perlakuan Al 2 (SO 4 ) 3 lebih sempit dari perlakuan NaOH dan lebih lebar dari spektrum ekstrak gambir. Hal ini menandakan adanya stretching gugus OH (senyawa fenol) (Hajar et al, 2016).…”

“…Puncak serapan yang kedua dari tinta stempel dariekstrak gambir dengan pengomplek NaOH 35% -NaOH 15% (2940, (Hajar et al, 2016;Maharani et al, 2016).…”

“…Pita serapan tinta stempel dengan pengomplek Al 2 (SO 4 ) 3 35% -Al 2 (SO 4 ) 3 15% adalah 1020,13 cm -1 -1034 cm -1 mengindikasikan gugus fungsi C-O dengan tipe senyawa alkohol (Hajar et al, 2016;Maharani et al, 2016). Muncul tiga puncak serapan baru tinta stempel (pengomplek NaOH dan Al 2 (SO 4 ) 3 yakni puncak out-ofplane (OOP) aromatik.…”