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The purpose of this paper is to investigate the inhibition effect of hydralazine hydrochloride as a corrosion inhibitor for mild steel in 1M HCl. The inhibition effect was studied at different temperatures, ranging from 303 to 333°K.

The inhibition efficiency of hydralazine hydrochloride was analyzed using weight loss, Tafel polarization, electrochemical impedance spectroscopy and surface morphology methods. The effect of temperature on the corrosion behavior of mild steel in 1M HCl was studied and discussed using an adsorption isotherm and activation parameters.

Weight loss, polarization and impedance showed that the inhibition efficiency increases with an increase in the concentration of hydralazine hydrochloride for mild steel in 1M HCl. The inhibitive action may be attributed to the adsorption of the inhibitor molecule on the active sites of the metal surface by the Langmuir adsorption isotherm. Polarization curves indicated that hydralazine hydrochloride acts as a mixed-type inhibitor. Scanning electron microscopy was performed on inhibited and uninhibited mild steel samples to characterize the surface. Thermodynamic parameter indicated that the adsorption of hydralazine hydrochloride is a spontaneous process and the adsorption occurs chemically.

The inhibition effect of hydralazine hydrochloride for mild steel has been investigated at different temperatures, ranging from 303 to 333°K. Hydralazine hydrochloride was a good inhibitor at a higher temperature.

The purpose of this investigation was to evaluate the protective ability of 2-amino-N-octadecylacetamide (AOA) and 2-amino-N-octadecyl-3-(4-hydroxyphenyl) propionamide (AOHP) as corrosion inhibitors for N80 steel in 15 per cent hydrochloric acid (HCl), which may find application as eco-friendly corrosion inhibitors in acidizing processes in the petroleum industry. Due to scale plugging in the well bore, there can be a decline in the crude production rate, and an acidization operation has to be carried out, normally by using 15 per cent HCl to remove the scale plugging. To reduce the aggressive attack of HCl on tubing and casing materials (N80 steel), inhibitors are added to the acid solution during the acidifying process.

Different concentrations of the synthesized inhibitors AOA and AOHP were added to the test solution (15 per cent HCl), and the corrosion inhibition efficiencies of these inhibitors for N80 steel were calculated from weight loss determinations, potentiodynamic polarization scans and alternating current (AC) impedance measurements. The influence of temperature (298-323 K) on the inhibition behavior was studied. Surface examinations were performed by means of Fourier transform infrared spectra and scanning electron microscope.

AOA and AOHP at 150-ppm concentration showed a maximum efficiency of 90.04 and 94.97 per cent, respectively, at 298 K in 15 per cent HCl solution. Both the inhibitors acted as mixed corrosion inhibitors. The adsorption of the corrosion inhibitors at the surface of the N80 steel was the underlying mechanism of corrosion inhibition.

This paper reports the preliminary laboratory results of inhibitors AOA and AOHP for the corrosion prevention of N80 steel casings and tubulars exposed to HCl and may be of practical help to petroleum engineers for carrying out acidization in oil wells after further investigation of the compound at higher temperature.

This paper aims to analyze the corrosion and corrosion inhibition of N80 in 10 per cent HCl + 8 per cent fluoroboric acid (HBF₄) solution for acidizing operation.

The corrosion rate, kinetic parameters (Ea, A) and thermodynamic parameters (ΔH, ΔS) of N80 steel in fresh acid and spent acid, 10 per cent HCl + 8 per cent HBF₄, 10 per cent HCl and 8 per cent HBF₄ solutions were calculated through immersion tests. The corrosion and inhibition properties were studied through X-ray diffraction and electrochemical measurements. The corrosion morphology of the corrosion product was examined by scanning electron microscopy (SEM).

The results demonstrated that the spent acid was the main cause of acidification corrosion, and the HBF₄ would cause serious corrosion to N80 steel. The results showed that the N80 steel was more seriously corroded in the spent acid than in fresh acid, and the hydrolysis of HBF₄ accelerates the dissolution process of N80 steel anode to control the corrosion reaction. The results showed that the acidification will definitely cause serious corrosion to the oil tube; therefore, necessary anti-corrosion measures must be taken in the acidification process.

The results showed that acidizing the formation with 10 per cent HCl + 8 per cent HBF₄ will definitely cause serious corrosion to the oil tube, especially when the spent acid flows back. Therefore, necessary anti-corrosion measures must be taken in the acidification process, especially in the spent acid flowback stage.

This paper aims to describe the corrosion behavior and possibility of inhibition by corrosion inhibitor SA1-3 in acidizing solution (5 per cent hydrochloric acid [HCl] solution). The study aims to explain the mechanism of corrosion and inhibition of N80 steel in 5 per cent HCl solution to provide theoretical basis for expanding the range of application of N80 steel in acidification process.

This paper opted for a laboratory study using simulation of acidizing solution to do the experiments. The results of experiments including weight-loss method, electrochemical method and surface analysis were used to explain the mechanism of corrosion and inhibition so as to predict the dissolution progress of N80 steel in 5 per cent HCl solution with and without inhibitor SA1-3.

This paper provides theoretical insights about how to inhibit the corrosion behavior of N80 steel in 5 per cent HCl solution. It suggests that the corrosion inhibitor which can form a protective film on the steel surface should be used to expand the application of N80 steel in acidizing solution. The inhibitor SA1-3 is a kind of cathodic corrosion-controlling inhibitor which mainly inhibits cathode corrosion; it cannot change the corrosion mechanism of N80 steel.

This paper provides a theoretical basis for the corrosion behavior and inhibition mechanism of N80 steel in acidizing solution.

The purpose of this paper is to produce an electroactive monomer containing ketonic resins and then to investigate redox reaction between Fe+3 and bounded thiophene in comonomers. First, thiophene functionalised ketonic resins (Th-CFPDMSR) were synthesised by esterification reaction of thiophene-2-carbonyl chloride (ThCCl) and hydroxyl groups of cyclohexanone formaldehyde resin (CFR). Th-CFPDMSR was then polymerised by ferric salt. Thiophene modified ketonic resins (Th-CFPDMSR) as comonomers were characterised by common techniques such as gel permeation chromatography, proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimeter and scanning electron microscope.

Th-CFPDMSR comonomers were synthesised by esterification reaction of ThCCl and hydroxyl groups of ketonic resins. Then, the in-situ chemical oxidation (ISCO) of ThC-CFR in the presence of iron (III) chloride salt (FeCl3) was accomplished in chloroform/acetonitrile mixture solutions at room temperature.

Important structural factor determined quantitatively for Th-CFPDMSR is the CFPDMS/TCCl ratio after reaction. The mole ratio effect of TCCl and ketonic resin on the solubility, molecular weight, melting temperature (Tm) and glass transition temperature (Tg) values of the comonomers (TCCl-CFPDMSR) was investigated.

The ferric ion (Fe+3) has a standard oxidation potential. Furthermore, FeCl3 can react with thiophene to produce a cation radical. FeCl3 cannot react with hydroxyl groups of ketonic resins. When ferric is used for ISCO application at relatively low temperatures (e.g. < 20°C), the oxidation reactions are usually less aggressive.

This work provides technical information for the synthesis of conducting block copolymer and for the synthesis of chain-extended resins. The modified resins contain thiophene. The chemical oxidation system has been used to polymerise these thiophene groups, and resins with much higher molecular weight might be produced. The resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating.

Novel Th-CFPDMSR comonomers were synthesised. These comonomers have higher Tg and Tm values than CF-PDMSR alone. The chemical oxidation system has been used to polymerise these thiophene functionalised ketonic resins.

Reviews some of the reactions of formaldehyde ‐ an important building block in the manufacture of speciality, performance chemicals and polymers ‐ with the intention of stimulating research into further uses of formaldehyde.

The aim of this paper is to solve the problem of carbonaceous deposits in automotive engines by preparing different ashless detergent/dispersant additives based on propylene oxide (PO) and different amines. Carbonaceous deposits in automotive engines are the major problems associated with oil aging. Efficient detergents and dispersants have been used to solve this problem, particularly in lubricating oils.

The structures of the prepared compounds were confirmed using Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC) for determination of molecular weight. This was followed by the evaluation of the prepared compounds such as detergent/dispersant and antioxidants additives for lubricating engine oil using several techniques such as variation of viscosity ratio, change in total acid number, optical density using infrared techniques, spot method, determination of sludge and determination the potential detergent dispersant efficiency (PDDE).

All the prepared compounds were found to be soluble in lubricating oil. The efficiency of the prepared compounds such as antioxidant and detergent/dispersant additives for lubricating oil was investigated. It was found that the additives have excellent power of dispersion, detergency and the most efficient additives such as antioxidant those prepared by using n,n-dimethyloctadecylamine (NDOA) and di-n-butyl dithio phosphoric acid.

The paper includes preparation of new compounds from the reaction of propoxylated amines and different organic acids and evaluates them as detergent/dispersant and antioxidants additives by using several techniques.

This paper fulfils an identified need to prepare new compounds from the reaction of propoxylated amines and different organic acids and evaluates them as additives by using different methods. All were found to have better efficiency as compared with commercial additives.

This work aims to synthesize a series of novel acyclic and/or heterocyclic systems, as precursors for dyes with potential antimicrobial activity that could be used for simultaneous dyeing and antimicrobial textile finishing. Thus, a series of novel pyridine, thiophene and pyrazolo[3,4-b]pyridine derivatives were synthesized, and their antimicrobial and textile finishing properties were studied and evaluated.

The synthesis, structure elucidation and antimicrobial activities of the newly synthesized compounds based on 4,4-dicyano-3-phenyl-but-3-enoic acid phenylamide (1) were demonstrated. The minimal inhibitory concentration in μg/mL of the compounds showed significant antimicrobial activity against most of the tested organisms. On the other hand, their spectral characteristics and fastness properties were measured and evaluated. Antimicrobial activities of the dyed fabrics in terms of inhibition zones (mm) were measured and evaluated.

A series of novel heterocyclic compounds (Schemes 1-3) were synthesized based on starting material (1). Compounds (1), 2, 4a, 8a and 9c exhibited comparable or even higher antibacterial activities than the selected standards (ampicillin), while compounds 2, 3c, 3d, 4a and 8b revealed higher antifungal activities than the selected standard (cycloheximide). On the other hand, some dyes showed high antimicrobial evaluation on the dyed fabrics (nylon 66, acetate and polyester) expressed as size (mm) of inhibition zones (Tables I-IV).

Results revealed that many hydrazo and azo derivatives were synthesized from some pyridines and thiophenes. The antimicrobial evaluation and textile finishing of the newly synthesized products revealed significant and potent values of antimicrobial activity.

All the synthesized compounds were novel and most of them exhibited higher antimicrobial activities than the selected standards antibiotics, thus are valuable for simultaneous dyeing and antimicrobial functional finishing of textile fabrics.

The purpose of this paper is to report the synthesis of resins having conducting and fluorescence properties, with carbazole and oligocarbazole with a one step method of in situ modification of ketonic resin. Cyclohexanone‐formaldehyde (CFR), and acetophenone‐formaldehyde (AFR) resins were in situ modified with carbazole in the presence of sodium hydroxide.

Carbazole modified ketonic resins were synthesised by the condensation reaction of Cz, formaldehyde and ketone. Oligo carbazole was synthesised by redox reaction of carbazole and ceric ammonium nitrate (CAN). Then, for the in situ modification of oligo carbazole modified ketonic resin, reaction mixture of oligocarbazole carbazole was added to the cyclohexanone/formaldehyde solution.

The carbazole modified cyclohexanone‐formaldehyde and acetophenone formaldehyde resins have conductivity values of 10⁻⁵‐10⁻⁶ S/cm and may be considered as semi‐conductive ketonic resins. These new carbazole modified ketonic resins (CCzFR, ACzFR) have fluorescence properties.

This study focused on obtaining a conductive and fluorescence resin using a carbazole monomer which is an insulator.

This study provides technical information for the synthesis of fluorescence comonomer.

New CCzFR, ACzFR comonomers were synthesised. These comonomers have higher Tm values than CFR and AFR alone and also have fluorescence property.

The purpose of this paper is to synthesize some novel 2-amino-6,6-dimethyl-9-phenyl-3-(phenyldiazenyl)-6,7-dihydropyrazolo-[5,1-b]quinazolin-8(5H)-one derivatives by multi-component one-pot reaction using a microwave as a new tool for green chemistry.

An equimolor from arylazopyrazole, 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and benzaldehyde derivatives was dissolved in Dimethylformamide (DMF) to be irradiated in a microwave for 15 minutes; after completion of the reaction, as indicated by Thin layer chromatograph (TLC), the reaction mixture was poured into ice water, filtered and then crystallized with an appropriate solvent.

The structure of the synthesized dyes was established and confirmed for the reaction products on the basis of their elemental analysis and spectral data (MS, IR and 1H-NMR). These prepared dyes were used to print polyester and polyamide fabrics using synthetic thickener in the printing paste for the silk screen technique. The synthesized dyes are superior in terms of yield, purity, color strength and fastness properties and will lead to valuable achievements for commercial production.

An efficient method for synthesis of pyrazoloquinazolinone dyes was designed. The novel procedure features short reaction time, moderate yields and simple workup. The authors studied its application in printing polyester and polyamide fabrics.