Adsorption behavior and corrosion rate model of sodium carboxymethyl cellulose (Na-CMC) polymer on aluminium in HCl solution

Adsorption behaviour and corrosion rate of Sodium carboxymethyl cellulose on aluminium was studied. Different concentration levels of Sodium carboxymethyl cellulose (Na-CMC) solution were applied on several prepared and polished aluminium coupons for a corrosion experiment. These coupons were totally immersed in 100ml of 0.5M solution of Hydrochloric acid (HCl) in an open beaker placed in a water bath at varying temperatures for 2-8hrs respectively. At every specified temperature and time interval, the immersed coupon specimen was withdrawn from the test solution, washed, dried and reweighed. The weight loss being the difference in weight of the specimen before and after immersion in the water bath was recorded for every coupon sample. The effects of concentration, temperature and time on corrosion rate were studied and from the various plots, it was observed that increase in the concentration of the inhibitor decreases the corrosion rate. The study of the adsorption behaviour showed that Na-CMC was physically adsorbed on the aluminium coupons and obeyed Freundlich adsorption isotherm with an activation energy of 32K.83j/mol and heat of adsorption of -18.21Kj/mol . The study also established a relationship between the corrosion rate, CR; concentration, C; temperature, T; and time t, through a mathematical model: CR = 3.8-5*T1.1617 - 0.00052t0.6176 - 0.0013C0.8012, the proportion of variance explained (R2) = 0.8658 (86.58%), From the Results of the experiment and the model, Na-CMC was found to be an active corrosion inhibitor of Aluminium in acidic environment. Keywords: Adsorption, Aluminium, concentration, Corrosion Rate, Weight Los

Effect of Particle Sized Clay Extender Pigment on Alkyd Paint Formulations

The effects of particle sizes on the properties of Ihitte-Uboma clay formulated alkyd paints have been studied. The clay particle sizes studied are 75, 150and 300 µm at clay contents 0 – 80 wt. %. Xylene was used as the solvent while TiO2 formulated alkyd paint served as reference alkyd paint in this study. The extender pigments were characterized using X-ray fluorescence and scanning electron microscope. The physic-chemical properties of the extender pigments were determined using ASTM measurements. The properties of the paint samples were evaluated according to ASTM. Results showed that the alkyd paints had higher viscosities which increased with increases in clay contents at the three clay particle sizes investigated. The drying properties of the paints were generally good. The dry film thicknesses of the formulated paints were in the range of 0.29 – 0.38 mm. The formulated paints exhibited moderate settling tendencies at the 75 µm clay particle size when compared with the other particles. There was no mildew formation observed on all the paint samples on exposure to rain and sunlight. Generally, all the paint samples exhibited good resistance to distilled water, 3 % H2SO4, and 3 % Na2CO3. The formulated paint samples were affected on 3 % NH3 immersion which resulted to wrinkles. The improved properties obtained from the clay formulated paints which include thermal and colour stability, viscosity, specific gravity

Protection of Mild Steel Corrosion in Sulphuric Acid Environment Using Wheat Starch

Abstract. The corrosion of mild steel in 0.5 M H 2 SO 4 acid solution and the inhibition process by wheat starch (WS) was investigated using weight loss and potentiodynamic polarization measurement techniques respectively. Gravimetric results revealed that there is significant reduction in the corrosion rate of mild steel in the presence of inhibited solution compared to blank solution, and also the inhibition efficiency was found to depend on the concentration of the WS. Data on potentiodynamic polarization results confirmed that WS exhibited mixed type inhibition behaviour, though the cathodic effect was more pronounced. The mode of WS adsorption on the corroding metal surface followed Langmuir isotherm model. In addition, the trend of inhibition efficiency with temperature, activation energy and heat of adsorption parameters revealed a strong interaction between the WS constituents and the corroding metal surface, thus indicating that WS lowered the corrosion process by blanketing the mild steel surface through chemical adsorption mechanism. The mechanism of inhibition was discussed in the light of the chemical structure of starch

Methacrylic Acid as Chemical Treatment on the Properties of Kapok Husk Filled Linear Low Density Polyethylene Eco-Composites

The effect of methacrylic acid (MAA) as chemical treatment on the properties of kapok husk (KH) filled linear low density polyethylene (LLDPE) has been studied. KH, as natural filler was added into LLDPE by using Brabender Plasticizer EC plus at temperature 160 °C. The addition of KH content decreased the tensile strength and elongation at break of the eco-composites, but modulus of elasticity increased. Crystallinity of LLDPE/KH eco-composites decreased with increasing of KH content. Chemical treatment by MAA altered the tensile properties and crystallinity of eco-composites. The treated LLDPE/KH eco-composites showed higher tensile strength, modulus of elasticity and crystallinity of eco-composites due to better interfacial interaction between LLDPE matrix and KH filler. This has proven by Scanning Electron Microscopic (SEM)

Adsorption and corrosion inhibition characteristics of 2–(chloromethyl) benzimidazole for C1018 carbon steel in a typical sweet corrosion environment: Effect of chloride ion concentration and temperature

Benzimidazole derivatives are emerging as promising corrosion inhibitors for oil and gas application because they exhibit high efficiency and very good environmental profile. Although long alkyl and phenyl chains enhance their efficiency, they also increase their toxicity. Finding benzimidazole derivatives devoid of long hydrocarbon chains and with lower toxicity has become a priority. 2–(chloromethyl)benzimidazole (CMB), with log Po/w = 2.2, has been investigated as a promising low-toxic sweet corrosion inhibitor for C1018 carbon steel in CO2–saturated NaCl solution under static condition using experimental and theoretical approaches. At 25 ◦C, Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) techniques confirm that CMB is an anodic-type sweet corrosion inhibitor which is able to form a protective layer on the steel surface and provide inhibition efficiency of 97.54% at 10 ppm. The efficiency increased to 98.40% and 98.58% upon increasing the temperature to 40 ◦C and 60 ◦C, respectively but decreased to 96.32% and 94.76% as the salt concentration was raised to 5.0% and 7.0% NaCl, respectively. The latter was attributed to the antagonistic competition between Cl– ions and CMB for anodic adsorption. The CMB–steel interaction is facilitated by the free electrons around N heteroatoms and C = C bonds, based on FTIR analysis and computational calculations. This eventually ameliorates the surface degradation of the steel during the sweet corrosion at 25 and 60 ◦C. CMB performance is highly comparable with reported sweet corrosion inhibitors with higher toxicity values