scholarly journals Corrosion Inhibition Efficiencies of Polymeric Materials on Alloy Steel in Dilute Hydrochloric Acid and Sodium Hydroxide Solutions at Ambient Temperature

2020 ◽  
Vol 7 (2) ◽  
pp. C27-C32
Author(s):  
I.E. Ekengwu ◽  
O.G. Utu ◽  
K.O. Anyanwu
Keyword(s):  
Corrosion Rate ◽  
Ambient Temperature ◽  
Alloy Steel ◽  
Corrosion Inhibition ◽  
High Density Polyethylene ◽  
Inhibition Efficiency ◽  
Polymeric Materials ◽  
High Density ◽  
Alkaline Solutions ◽  
Ph Values

A corrosion control test was conducted on alloy steel, using polymeric coatings (polyurethane, bitumen (medium airing), and high-density polyethylene) in dilute HCl solutions of pH values 4, 7, and 12, respectively for acid, neutral and alkaline solutions at ambient temperature. In the study, Eighty-four coupons of alloy steel were used. The coupons were mechanized, ground, polished, etched with natal, and weighed using a digital weighing balance (Beva 206B). The mass of each coupon was recorded according to the tag number on them. Twenty-one of the coupons were coated with polyurethane, 21 coated with medium curing bitumen (MC), and 21 coated with high-density polyethylene, while 21 were left uncoated. Seven polyurethane-coated samples, bitumen coating, and uncoated coupons were suspended in dilute HCl solutions of pH values 4, 7, and 12. Every week, one sample is taken from each of the solutions, the coatings and the corrosion products were removed, and the coupons were etched with natal. Then the coupons were reweighed, and their masses were recorded in accordance with their tag number. The weight loss per unit area of the coupons, corrosion rate, and percentage corrosion inhibition efficiencies of the coatings was calculated over seven weeks. The results obtained were tabulated and represented graphically. From the results obtained, it is seen that the corrosion inhibition efficiency of polyurethane coatings is higher compared with bitumen and polyethylene. It is also seen from the graphs that the corrosion rate of the coupons is higher in acid, a little bit lower in alkaline, and much lower in neutral solution. It is also observed that the corrosion rates fall with time as the inhibition efficiency also falls with time.

scholarly journals Effect of Sodium Chloride on Corrosion Inhibition Efficiency of Polyethylene Coatings on Alloy Steel at Ambient Temperature

2020 ◽  
Vol 7 (1) ◽  
pp. C9-C13
Author(s):  
K. O. Anyanwu ◽  
I. S. Ogu ◽  
H. O. Nzei
Keyword(s):  
Sodium Chloride ◽  
Corrosion Rate ◽  
Alloy Steel ◽  
Corrosion Inhibition ◽  
Inhibition Efficiency ◽  
Chloride Concentration ◽  
Distilled Water ◽  
Sodium Chloride Concentration ◽  
Plastic Container ◽  
Corrosion Inhibition Efficiency

An investigation was conducted on the effect of sodium chloride concentration on corrosion inhibition efficiency of High-Density Polyethylene (HDP) coating on alloy steel in sodium chloride solutions of different degrees of salinity. In the study, four test media were used: the first is 20 l of distilled water in a rectangular base plastic container; the second is 20 l of distilled water in a rectangular base plastic container in which 200 g of sodium chloride (NaCl) was dissolved entirely, giving a concentration of 10 g/l (0.01 g/cm²). Similarly, the third medium is 20litres of distilled water in which 300 g of NaCl was dissolved entirely, having 15 g/l (0.015 g/cm²) concentration. The fourth medium is prepared by dissolving 400 g of NaCl in 20litres of distilled water, resulting in 20 g/l (0.02 g/cm²) concentration. The container used for each medium is a rectangular base plastic container. Twenty-eight (28) uncoated and twenty-eight (28) polyethylene-coated alloy steel coupons of dimension 5×30×50 mm with an 8 mm diameter hole each were used for this investigation. Seven coated coupons each were wholly immersed in 10, 15, and 20 g/l, and zero salinity distilled water. Similarly, seven uncoated coupons each were immersed entirely in 10, 15, and 20 g/l and zero salinity distilled water. The coupons in various test media were exposed to ambient temperature for a total of 49 days. One coupon from each of the media is reweighed on weekly bases and the weight loss (g), corrosion rate (mm/year), and corrosion inhibition efficiency were calculated and recorded. From the results obtained, the corrosion rate of the coupons increases with an increase in sodium chloride solution. It is also observed from the results obtained considering the variation of corrosion rates of polyethylene coated coupons with sodium chloride concentration and the variation of corrosion rates of uncoated coupons with sodium chloride concentration that the corrosion rate of the coupons is lesser with the polyethylene coating compared with the uncoated coupons. The results show that the corrosion rate of coupons falls over time, and more rapidly at an early time of exposure, say the first week. From the result of the variation of corrosion inhibition efficiencies of polyethylene coated coupons with sodium chloride concentration, it is observed that the corrosion inhibition efficiency of polyethylene decreases over time and decrease also with an increase in sodium chloride concentration. Keywords: alloy steel, coating, corrosion inhibition, high-density polyethylene, sodium chloride.

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.

Electrical and dielectric sensitivities to thermal processes in carbon nanofiber/high-density polyethylene composites

2011 ◽  
Vol 18 (1-2) ◽  
pp. 51-60 ◽  
Author(s):  
Tian Liu ◽  
Weston Wood ◽  
Bin Li ◽  
Brooks Lively ◽  
Wei-Hong Zhong
Keyword(s):  
Dielectric Properties ◽  
Thermal Treatment ◽  
High Density Polyethylene ◽  
Ac Conductivity ◽  
Elevated Temperatures ◽  
Carbon Nanofiber ◽  
Polymeric Materials ◽  
High Density ◽  
Heating Process ◽  
Thermal Processes

AbstractOwing to the huge interface region existing in a polymer nanocomposite, the effects of thermal processes on properties of nanocomposites are much more complicated than in a pure polymer. It is therefore important to determine the effects of thermal processes on nanocomposites with different interfacial interactions between the nanofillers and the polymer matrix. It is also important to explore the performance changes for nanocomposites under elevated temperatures over pure polymers. In this investigation, we examined the correlation of thermal treatment with dielectric properties of carbon nanofiber (CNF) reinforced high-density polyethylene nanocomposites. The thermal treatment of specimens was conducted for up to 120 h at 87°C and 127°C. Then, alternating current (AC) conductivity and dielectric properties were tested after definite intervals of time. Their changing rates over treatment time were analyzed. The results revealed the approximate linear relationships of AC conductivity and dielectric constant vs. heating time. Modified CNF reinforced nanocomposites had less influence by the heating treatments exhibiting better thermal resistance. The change rates of AC conductivity σ and dielectric properties have higher sensitivity to the treatment at a higher temperature. This study provides potential for further research on application of electrical and dielectric signals to detect the effects of heating process on lifetime of polymeric materials.

Nanocomposite Polymeric Materials Based on Butyl Rhodamine B Incorporated in Mesoporous Films of High-Density Polyethylene

2020 ◽  
Vol 90 (4) ◽  
pp. 737-742
Author(s):  
O. V. Arzhakova ◽  
A. A. Dolgova ◽  
A. Yu. Kopnov ◽  
A. I. Nazarov ◽  
A. Yu. Yarysheva ◽  
...  
Keyword(s):  
Rhodamine B ◽  
High Density Polyethylene ◽  
Polymeric Materials ◽  
High Density ◽  
Mesoporous Films ◽  
Butyl Rhodamine B

Study on the solidification kinetics of high-density polyethylene during thin-walled injection molding process

2012 ◽  
Vol 32 (6-7) ◽  
pp. 355-363 ◽  
Author(s):  
Shuang-quan Deng ◽  
Bin Yang ◽  
Ji-bin Miao ◽  
Ru Xia ◽  
Jia-sheng Qian ◽  
...  
Keyword(s):  
Injection Molding ◽  
High Density Polyethylene ◽  
Polymeric Materials ◽  
High Density ◽  
Injection Molding Process ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Molding Process ◽  
Solidification Kinetics ◽  
Thin Walled

Abstract In this work, the effect of the initial and secondary temperature differences on the solidification behaviors of high-density polyethylene (HDPE) during the thin-walled injection molding (TWIM) was intensively investigated. Simulated temperature profiles using the enthalpy transformation methodology were compared with an in situ temperature measurement, and reasonable agreement was achieved between calculations and measurements. Two-dimensional wide-angle X-ray diffraction characterization shows that the formation of oriented crystal structures was considerably affected by the thermal gradient within the injection-molded article. The present study can be practically significant to the optimization of the cooling parameters during the TWIM of crystalline polymers as well as to the further study on the relationship among “processing-structure-property” of polymeric materials.

scholarly journals Corrosion Inhibition Behaviour of Enantia chlorantha Extract on Pipeline Steel Corrosion in Acidic System

2020 ◽  
Vol 24 (4) ◽  
pp. 707-712
Author(s):  
N.C. Ngobiri ◽  
C. Obi
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Surface Coverage ◽  
Inhibition Efficiency ◽  
Pipeline Steel ◽  
Gravimetric Method ◽  
Acidic Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition capacity of Enantia chlorantha bark (ECB) extract on the corrosion of pipeline steel in an acidic environment was studied using the gravimetric method. The result revealed that weight loss obviously increased with the rise in temperature though trend lines were not parallel. The results obtained from the evaluation showed that the corrosion inhibition efficiency of the extract increased with extract concentrationattaining an efficiency of 89.02% with 2.5 g/L concentration at 30 ºC. The corrosion inhibition efficiency, however, decreased with increase in temperature, while the corrosion rate decreased. The significant achievement in this study was the ability of Enantia chlorantha extract to reduce the corrosion rate constant, increase its surface coverage with consequent longer material half-life in an acidic environment. Keywords: Inhibition efficiency, surface coverage, plant extract, weight loss, half-life

scholarly journals CORROSION INHIBITION OF CARBON STEEL IN HYDROCHLORIC ACID

2021 ◽  
Vol 21 (3) ◽  
pp. 197-212
Author(s):  
Falah Kaify Matloub
Keyword(s):  
Carbon Steel ◽  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Corrosion Inhibition ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Cathodic Reaction ◽  
Anodic Reaction ◽  
Organic Inhibitor ◽  
Better Than

The corrosion of carbon steel in 0.3 and 3% mass hydrochloric acid containing the concentration range 50-800 ppm of Thiourea (Th), Quinoline (Q), Dliethylamine (DEA) and Pyridine (P) were investigated using electrochemical methods. The investigation aims to mention the best organic inhibitor among several compounds to be used in synergic inhibitors. The inhibition efficiencies of thiourea and quinoline are better than pyridine and diethylamine in 0.3 mass% HCl. Thiourea is better than quinoline in 3 mass% HCl and its inhibition efficiency is 83.7%. Generally, the corrosion rate decreases with increasing inhibitors concentration. Diethylamine and pyridine are not effective. The polarization curves indicate that the used inhibitors influenced the cathodic reaction more than the anodic reaction and they are considered as a mixed type inhibitors

Breathable polymeric materials based on high‐density polyethylene prepared by environmental crazing

2019 ◽  
Vol 137 (15) ◽  
pp. 48567
Author(s):  
Alena Yarysheva ◽  
Ekaterina Rukhlya ◽  
Tatyana Grokhovskaya ◽  
Alla Dolgova ◽  
Olga V. Arzhakova
Keyword(s):  
High Density Polyethylene ◽  
Polymeric Materials ◽  
High Density

scholarly journals Corrosion Inhibition of Carbon Steel using Dipropyl Sulphide as Inhibitor System in Sulphuric Acid Solution

2021 ◽  
Vol 33 (12) ◽  
pp. 3115-3122
Author(s):  
P. Vijayakumar ◽  
S. Valarselvan ◽  
S.S. Syed Abuthahir
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Sulphuric Acid ◽  
Surface Analysis ◽  
Corrosion Inhibition ◽  
Steel Surface ◽  
Inhibition Efficiency ◽  
Protective Film ◽  
Carbon Steel Surface ◽  
Loss Method

The corrosion inhibition effect of dipropyl sulphide (DPS) on carbon steel immersed in 0.5 N sulphuric acid has been evaluated at room temperature using mass loss method. The corrosion rate and inhibition efficiency was obtained from weight loss method. The corrosion inhibition efficiency increases with increase in concentration of an inhibitor. The corrosion rate decreases when increase in concentration of inhibitor. This is due to the higher concentration of inhibitor solution, which blocks the active site of a carbon steel and a protective film is formed on the carbon steel surface. Electrochemical studies have been used to confirm the formation of protective film over the carbon steel surface. This is further confirmed by surface analysis technique like FTIR spectroscopy and scanning electron microscopy. Energy dispersive analysis of X-ray was used to analyze the elements present over the carbon steel surface. Surface analysis of polished, corroded and inhibitor carbon steel surface has been evaluated by SEM. In order to study adsorption of dipropyl sulphide on carbon steel, in situ atomic force microscopy (AFM) measurements were performed in control, with and without dipropyl sulphide in 0.5 N H2SO4 solution.

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