Cassava starch graft copolymer as a novel inhibitor for the corrosion of aluminium in HNO3 solution
Graphical abstract
Introduction
Corrosion protection of aluminium in HNO3 water solution has been an important topic in the metal protection area because HNO3 is widely used for cleaning sedimentary scale. Aluminium typically shows a slower dissolving rate in HNO3 than HCl [1], which was attributed to the different corrosion mechanism. Aluminium dissolution mechanism in HCl was largely investigated and almost clearly understood [1]. On the other hand, the corrosion details of aluminium in HNO3 still remain somewhat uncertain though some studies have been dedicated to investigating the corrosion behavior and mechanism of aluminium in HNO3 media [[1], [2], [3], [4], [5]]. Accordingly, the corrosion behavior of aluminium in HNO3 is rather more complex than that in HCl.
To protect aluminium from acid corrosion, inhibitors are always added to the acid solution during cleaning. Comparing with many efficient inhibitor studies for aluminium in HCl, very little attention has been paid to corrosion inhibition of aluminium in HNO3. Most of the efficient inhibitors in HCl solution can lose their inhibitive ability in HNO3 solution [6]. The studies about corrosion inhibitors for aluminium in HNO3 can be dated back to 1970s when Singh et al. [[7], [8], [9]] reported some thiourea and urea derivatives showing corrosion retardancy of aluminium in HNO3. Inhibitive ability followed the general order: naphthyl thiourea > phenyl thiourea > thiourea > urea, and the maximum inhibition efficiency of naphthyl thiourea was around 80% [8]. Afterwards, Yadav et al. [[10], [11], [12]] reported the inhibition effect of benzoic acids and various derivatives on aluminium corrosion in HNO3. Among these compounds, 3,4,5-trihydroxy benzonic acid was found to be the most effective inhibitor with inhibition efficiency of 72% in 20% HNO3. In 2010s, Khaled [13] investigated three sulphur-containing amines, 3-pyridinecarboxaldehyde thiosemicarbazone (META), isonicotinaldehyde thiosemicarbazone (PARA) and 2-pyridinecarboxaldehyde thiosemicarbazone (ORTHO) about the corrosion inhibition of aluminium in 1 0 M HNO3. The results showed that inhibition efficiency followed an order: META > PARA > ORTHO, and the maximum inhibition efficiency of 0.01 M META was 88.4% at 25 °C. Obviously, the efficient inhibitor of aluminium in HNO3 solution is still rather scarce, and it is necessary to explore more inhibitors. These compounds reported in previous literatures [[7], [8], [9], [10], [11], [12], [13]] were typically small organic molecules, and so the question whether polymer compound is well qualified for potential effective inhibitor for aluminium in HNO3 medium has been emerged.
Compared with low molecular inhibitor, the polymer inhibitors were expected to have larger coverage surface, hence better inhibition performance and stability [14]. Some polymers like petrochemical compounds such as tweens [15], polyxoyethylene mono oleates [16] and poly 3-(decyloxy sulfonic acid) aniline [17] as well as natural polymers such as pectin [18], iota-carrageenan [19] and exudate gum [20] were also reported to be able to inhibit aluminium corrosion in HCl solution. These efficient polymer inhibitors of aluminium in HCl do not necessarily exhibit good inhibitive performance in HNO3. Up to now, there is almost no study on using polymer as an inhibitor for aluminium corrosion in HNO3 solution.
Starch is one of the richest natural polymer resources in the world. It is safe, non-toxic and biodegradable with has low-cost. However, starch is seldom used as corrosion inhibitor due to the low corrosion retardency [21]. Recently, we have conducted some works to prepare cassava starch graft copolymer (CSGC) by grafting the vinyl monomer onto cassava starch (CS) with oxidization reduction reaction. To our surprise, CSGC was found to show high efficiency in inhibiting aluminium against in HCl solution [22,23], and the maximum inhibition efficiency was higher than 90% at CSGC concentration of 50 mg L−1. However, the adsorption mechanism of CSGC on aluminium surface needed to be further investigated, and the role of vinyl monomer in CSGC is still uncertain. The corrosion behavior and mechanism of aluminium in HNO3 is quite more complex than that in HCl, so it is still unclear whether CSGC is an effective corrosion inhibitor for aluminium in HNO3 media.
In this study, we firstly reported the inhibition effect of CSGC on the corrosion of aluminium in HNO3 solution. Effects of inhibitor concentration, temperature, immersion time and acid concentration on inhibition efficiency were fully examined by weight loss method. Both adsorption thermodynamic and corrosion kinetic parameters were calculated to assist in understanding the adsorption behavior of CSGC on aluminium surface. Meanwhile, the electrochemical inhibitive mechanism was proposed according to electrochemical techniques. The micro morphologies and compositions of aluminium surface in HNO3 solution were investigated by scanning electron microscope (SEM), atomic force microscope (AFM), contact angle images and X-ray photoelectron spectroscopy (XPS). Moreover, the adsorption of CSGC was theoretically studied by quantum chemical calculations and molecular dynamic (MD) simulations. Lastly, the corrosion reactions for aluminium in HNO3 solution and inhibitive mechanism of CSGC were proposed. It is expected to throw some light on seeking the efficient inhibitor for aluminium in HNO3 solution.
Section snippets
Materials
Aluminium specimen (Al 1060) with the composition (wt%): 0.25 Si, 0.35 Fe,0.05 Cu, 0.03 Mn, 0.03 Mg, 0.05 Zn, 0.03 Ti, 0.05 V and balance Al was obtained Yunnan Aluminium Co. Ltd. The aggressive solutions of 1.0–4.0 M HNO3 were prepared by dilution of analytical (AR) grade 65% HNO3 with distilled water. Industrial-grade CS (about 17% amylose and 83% amylopectin [24,25]) was purchased from Red River Hong Starch Co. Ltd. in Yunnan province of China. AR grade of acryl amide (AA) was obtained from
Raman spectra of CS and CSGC
Raman spectra of CS and CSGC are shown in Fig. 2(a) and (b), respectively. For CS in Fig. 2(a), the absorption peak at 2906 cm−1 was assigned to CH antisymmetric and symmetric stretching vibrations. The peaks in the region between 1500 and 1200 cm−1 can provide rich information of functional groups. A band at 1466 cm−1corresponded to CH, CH2, and COH deformation vibrations. The bands at 1382 and 1341 cm−1 can be assigned to COH deformation or CO stretching vibration. The peak at 1267 cm−1 was
Conclusions
- (1)
The grafting polymer of CSGC behaves as an effective inhibitor for aluminium corrosion in 1 0 M HNO3, and the maximum ηw is 93.3% at 1.0 g L−1 and 20 °C. The inhibitive performance of CSGC is higher than that of CS, AA, or CS/AA mixture. Inhibition efficiency increases with the concentration of CSGC, but decreases with the increase of temperature.
- (2)
The adsorption of CSGC on aluminium surface obeys Langmuir adsorption isotherm with ΔG0 of around −20 kJ mol−1, and it is an exothermic process
Acknowledgements
Funding support from the National Natural Science Foundation of China (51561027) and Training Programs of Young and Middle Aged Academic and Technological Leaders in Yunnan Province (2015HB049, 2017HB030) are acknowledged.
References (73)
- et al.
Degradability of aluminum in acidic and alkaline solutions
Corros. Sci.
(2014) - et al.
Repassivation and pitting of freshly generated aluminum surfaces in acidic nitrate solution
Corros. Sci.
(2005) - et al.
Inhibition and polarization studies of some substituted urea compounds for corrosion of aluminum in nitric-acid
Electrochim. Acta
(1981) Electrochemical investigation and modeling of corrosion inhibition of aluminum in molar nitric acid using some sulphur-containing amines
Corros. Sci.
(2010)- et al.
Application of carbohydrate polymers as corrosion inhibitors for metal substrates in different media: a review
Carbohydr. Polym.
(2016) - et al.
The effect of some ethoxylated fatty acids on corrosion of aluminium in hydrochloric acid solutions
Mater. Chem. Phys.
(1998) - et al.
Pectin as promising green corrosion inhibitor of aluminum in hydrochloric acid solution
Corros. Sci.
(2012) - et al.
Corrosion inhibition of iota-carrageenan natural polymer on aluminum in presence of zwitterion mediator in HCl media
Corros. Sci.
(2012) - et al.
The inhibition of aluminium corrosion in hydrochloric acid solution by exudate gum from Raphia hookeri
Desalination
(2009) - et al.
Cassava starch-sodium allylsulfonate-acryl amide graft copolymer as an effective inhibitor of aluminum corrosion in HCl solution
J. Taiwan Inst. Chem. Eng.
(2018)
Experimental and theoretical study on corrosion inhibition of oxime compounds for aluminium in HCl solution
Corros. Sci.
Fourier transform Raman and infrared spectroscopy of pectins
Carbohydr. Polym.
The infrared and Raman spectra and structure of arcylamide
J. Mol. Spectrosc.
The adsorption and corrosion inhibition of anion surfactants on aluminium surface in hydrochloric acid
Corros. Sci.
Inhibition effect of 6-benzylaminopurine on the corrosion of cold rolled steel in H2SO4 solution
Corros. Sci.
A effect of sodium dodecylsufate on the corrosion of copper in sulphuric acid media
Colloids Surf. A Physicochem. Eng. Asp.
Inhibition effect of Dendrocalamus brandisii leaves extract on aluminum in HCl, H3PO4 solutions
Corros. Sci.
New organic compounds based on siloxane moiety as corrosion inhibitors for carbon steel in HCl solution: weight loss, electrochemical and surface studies
J. Taiwan Inst. Chem. Eng.
Synergistic inhibition between o-phenanthroline and chloride ion on cold rolled steel corrosion in phosphoric acid
Mater. Chem. Phys.
Gravimetric, electrochemical and quantum chemical studies of some pyridazine derivatives as corrosion inhibitors for mild steel in 1M HCl solution
J. Taiwan Inst. Chem. Eng.
Electrochemical and theoretical investigation on the corrosion of aluminium in acidic solution containing some Schiff bases
Appl. Surf. Sci.
Relationship between structure and inhibition behavior of quinolinium salts for mild steel corrosion: experimental and theoretical approach
Corros. Sci.
Corrosion inhibition of mild steel by two new heterocyclic compounds in 1 M HCl: experimental and computational study
Corros. Sci.
Sodium molybdate as a corrosion inhibitor for aluminium in H3PO4 solution
Corros. Sci.
The potential of freshly generated metal surfaces determined from the guillotined electrode–a new technique
Corros. Sci.
Electrochemcial impedance spectroscopy as a tool to obtain mechanistic information on the passive behaviour of aluminium
Electrochim. Acta
Experimental and theoretical study for corrosion inhibition of mild steel in normal hydrochloric acid solution by some new macrocyclic polyether compounds
Corros. Sci.
The corrosion behaviour of Al–Zn–In–Mg–Ti alloy in NaCl solution
Corros. Sci.
Evaluation of inhibitive action of some quaternary N-heterocyclic compounds on the corrosion of Al-Cu alloy in hydrochloric acid
Mater. Chem. Phys.
Effect of cafazolin on the corrosion of mild steel in HCl solution
Corros. Sci.
Corrosion inhibition of carbon steel and antibacterial properties of aminotris-(methylnephosnic) acid
Mater. Chem. Phys.
The inhibition of benzimidazole derivatives on corrosion of iron in 1 M HCl solutions
Electrochim. Acta
Macrosegregation and microstructure dendritic array affecting the electrochemical behaviour of ternary Al–Cu–Si alloys
Electrochim. Acta
Determination of corrosion rates by electrochemical DC and AC methods
Corros. Sci.
Synergistic effect of iodide ion addition on the inhibition of mild steel corrosion in HCl by 3-amino-2-methylbenzylalcohol
Mater. Chem. Phys.
Quantum chemical studies on the inhibition of corrosion of copper surface by substituted uracils
Appl. Surf. Sci.
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