Modified cassava starches as corrosion inhibitors of carbon steel: An electrochemical and morphological approach

Renewable resources in corrosion resistance

“…The polarization resistance values followed the order CMS 0.13 <CMS 0.24 < GAS. The studies confirmed that starch acts as corrosion inhibitor of carbon steel; the extent of protection against corrosion depended on the amount and type of active groups present [carboxylate (-COO−) and alkoxy (-CO−) groups for CMS, and alkoxy (-CO−) groups for GAS] and also on DS (Bello et al, 2010). …”

“…These were characterized by NMR spectroscopy; estimation of DS was also performed, which was about 0.13±0.03 (CMS 0.13 ) and 0.24±0.04 (CMS 0.24 ). Electrostatic potential [V(r)] mapping of the repetitive unit of GAS and CMS was based on the model proposed by Politzer and Sjoberg (Bello et al, 2010). Corrosion studies were performed by EIS coupled with a rotating disk electrode with a fixed rotation speed of 1000 rpm.…”

Modified cassava starches as potential corrosion inhibitors for sustainable development

“…They were prepared from native cassava starch, provided by Agroindustriales Mandioca S.A., following the procedure described in previous works [31][32][33] . The success of the modification process was determined by means of Fourier Transform Infrared Spectroscopy (FTIR), using a Nicolet Magna IR 760 spectrometer with a resolution of 4 cm -1 , to obtain the spectra from films casted onto AgBr discs.…”

“…The success of the modification process was determined by means of Fourier Transform Infrared Spectroscopy (FTIR), using a Nicolet Magna IR 760 spectrometer with a resolution of 4 cm -1 , to obtain the spectra from films casted onto AgBr discs. The CMS degree of substitution was determined by back titration, with the experimental procedure described in previous investigations 32,33 .…”

“…It should be mentioned that in most of the works dealing with natural products as corrosion inhibitors, tests have been performed under acid conditions, and significantly less work has been published about the use of natural compounds in neutral-alkaline solutions 1,2,8,10,29 . More recently, we have reported that modified cassava starches exhibit corrosion inhibitive properties for carbon steel in a solution that simulates the chemical composition of tap water [31][32][33] . In this work, electrochemical measurements and X-ray Photoelectron Spectroscopy (XPS) analysis were coupled to investigate parameters such as type of modification, inhibitor concentration and time of immersion, with the aim of understanding the inhibition mechanism of these species.…”