28

CHAPTER-II

REVIEW OF LITERATURE

Several inhibitors have been used for cooling water systems. Many

chemical compounds singly or in formulations can be used as corrosion

inhibitors, particularly for steel in near neutral, aqueous solutions. Such

compounds include chromates, nitrites, phosphates phosphonates and

carboxylates of various molecular structures.

The principles and practice of corrosion inhibition in recent years have

become conscious to health and safety considerations. These relate to all aspects

of inhibitor practice i.e., handling, storage, use and disposal. The use of

hazardous chemicals has been restricted to limited use with no contact with

environment. The use of chromates and phosphates is restricted due to the

environmental health hazard. Hence there is a need for the use of non-toxic,

ecofriendly corrosion inhibitors. Carboxylic acids, their salts and their derivatives

have recently emerged as a new and potential class of corrosion inhibitors. Many

carboxylates such as salicylate1, cinnamate2, phenyl acetate,3 anthranilates4, thio

divalerate5, adipate6,7 and their derivatives have been used as inhibitors. Their

inhibitive action results from the bonding of the anion to the metal surface

through the excess e-s on the O- ion. Inhibitive anions such as benzoate, phthalate

and other carboxylates stabilize the oxide film on iron surface8,9,10. Review of

carboxylates as corrosion inhibitors have appeared from time to time.11-14

Mercer15 reviewed carboxylates that provide protection to cast iron and

non –ferrous metals in 1980.

Review of literature reveals the use of many organic acids, their salts or

their derivatives as corrosion inhibitors to various metals and alloys like Cu, Al

carbon steel, stainless steel etc., in various aqueous media (acids, alkaline and

neutral).

29

II.1: Amino acids and their derivatives as corrosion inhibitors:

Bereket and Yurt16 have studied the inhibition effect of amino acids and

hydroxy carboxylic acids on pitting corrosion of Al alloy in NaCl solution at

various pH levels by potentiostatic methods. Amino acids shift the Epit values to

noble direction in acidic solutions, while hydroxy carboxylic acids are effective

in neutral and basic solutions.

Yurt and Bereket17 have correlated the experimentally obtained inhibition

efficiencies of six amino acids and six hydroxy carboxylic acids for the corrosion

of Al alloy 7075 in NaCl with parameters such as electronic charge on active

centers, dipole moment, highest occupied and lowest unoccupied molecular

orbital energies etc based on quantum chemical calculations. Aksut and Bilgic18

have examined the inhibitive effect of amino acids on the passivity of Ni in

H2SO4

According to Pech and Bartolo19 the inhibitive effect of N-

phosphonomethyl glycine-Zn2+ mixture on corrosion of steel in neutral medium

is due to the retardation of anodic and cathodic processes due to the film, Fe-

inhibitor complex and ZnO. Zerfaoui et al20 have reported the corrosion behavior

of pure iron in citric acid in the presence of glycine, leucine, aspartic acid,

arginine, and methionine and they were found to act as cathodic inhibitors.

Abd-El-Nabey et al21 have investigated the influence of amino acids such as

cysteine, cystine, and methionine as corrosion inhibitors on the corrosion of

carbon steel in acid medium. Both anodic and cathodic polarization curves were

found to be affected. Amino carboxylic acids and their N-phosphonomethyl

derivatives with or without additives (Zn or metavanadate ion) have been studied

in neutral solution by Kalman et al22 Ashassi et al have investigated the

inhibitive action of alanine, glycine and leucine by potentiodynamic and

polarization methods towards the corrosion of steel23 and Al24 in acid medium.

Gamal and Mostaf125 have elucidated the effect of temperature and the molecular

30

structure of amino acids on the inhibition efficiency for the corrosion inhibition

of Cu electrode in 1M HCl solution.

II.2.Poly carboxylic acids and their derivatives as corrosion inhibitors :

Polymer having COOH group is one of the effective polymer based system.

There are several carboxylic acids of low molecular weight, which are used as

corrosion inhibitor to many inhibitor formulations. Rajendran et al26 Aramaki27

and Yuasa et al28 have studied the inhibitive effect of polyacrylate, polymaleic

and polymethacrylate along with other inhibitors. According to Yuasa et al29 the

inhibitive effect of polyacrylic acid –polyacrylamide is due to the formation of

polymer-polymer complex.

Bodo Muller et al30 have studied the corrosion inhibition of polymethacrylic

acid and styrene maleic acid co-polymer on zinc pigments in aqueous alkaline

medium. Abd El Rehim et al31 have discussed that the amino polycarboxylic

acids such as Ethylene glycol-bis (1-aminoethylether-N, N)tetraacetic acid,

diethylene triaminepentaacetic acid, ethylene diaminetetraacetic acid and nitrilo

acetic acid inhibit corrosion of steel in sulphate solutions at low pH and promote

corrosion above certain pH. An alkaline cooling water treatment program with

ATMP and sodium polyacrylate has been reported.32 The performance of HEDP

and acrylic acid base terpolymer have been evaluated.33

Bodo Muller34 has studied the corrosion inhibition of Al by various

polymers such as polyacrylic acid, styrene-maleic acid, styrene-acrylate co-

polymer, phenolic resins and polyvinyl alcohol (PVA). According to him ionic

interactions between the metal and inhibitor are essential for corrosion

inhibition.The behaviour of corrosion inhibition by various cationic polymers

such as polyethyleneimine derivative, polyacrylamide derivative,

polydicyanodiamide derivative and anionic polymers such as polymaleic acid

derivative, polyacrylic acid derivative and polyacrylic acid was investigated by

31

Sekine et al35. Shah et al 36 have discussed the use of antifoulants such as sodium

acrylate, sodium salt of polymaleic acid, carboxymethyl cellulose (CMC) and

tannin for clay and CaCO3 dispersion.

II.3. Substituted acids and their derivatives as corrosion inhibitors:

Nathalie Ochoa37 et al have studied the influence of fatty amines in

association with phosphono carboxylic acid salts on the corrosion of carbon steel.

Electrochemical studies38 of the corrosion inhibition of methionine ethyl ester of

iron in citric chloride solution has revealed that it is a mixed type indicator and it

acts on the cathodic reactions without changing the mechanism of hydrogen

evolution. Hydrazides of carboxylic acids39 were found to act as inhibitors, for

the corrosion of steel in acidic medium.

Ethoxylated fatty acids were found to act as corrosion inhibitor for carbon

steel in formation water40, for zinc in acidic medium41, Al in acidic medium42

and mild steel in acidic medium.43 Three long chain fatty acids 44 namely 2-

undecane-5-mercapto-1-oxa-3,4-diazole (UMOD), 2-heptadecene-5-mercapto-1-

oxa-3,4-diazole (HMOD) and 2-decene-5-mercapto-1-oxa-3,4-diazole (DMOD)

were found to act as mixed type of inhibitors for mild steel in acidic medium.

Adsorption mechanism was proposed.

Electrochemical studies were carried out on the influence of [(2-pyridine-4-

ylethyl) thio] acetic acid and pyridine on the corrosion of steel in H2SO4 solution

by Bouklah et al.45 The influence of diethyl pyrazine-2,3-dicarboxylate on the

corrosion of steel in 0.5 M H2SO4 solution was studied by Bouklah et al46 using

mass-loss and electrochemical methods .It is reported that the inhibitors act

essentially as a cathodic inhibitor.

Agarwal and Landolt47 have concluded that the inhibition efficiency of N-

ethyl-morpholine salts of a & amp; omega; - benzoyl alcanoic acid and benzoic

acid is the result of the passivation of the electrode due to the capacity of these

32

inhibitors to act as a buffer in the anodic diffusion layer, thus blocking the

surface sites for anodic dissolution. Radusev48 et al have studied the inhibitive

effect of hydrazides of fatty carboxylic acids on the corrosion of steel in HCl,

H2S and actual oil field water.

A comparative study of the inhibitive effect of amp; omega; benzoyl

alcanoic acid with benzoic acid for the corrosion of steel in different electrolyte

was carried out by Agarwal and Landolt.49 The inhibition of corrosion of mild

steel in H2SO4 by commercial surfactants alkyl phenyl ethoxide-2000 and alkyl

phenyl ethoxylate-400 has been studied50 and they are found to be mixed

inhibitors. Seliman et al51 have studied the inhibitive action of sodium

ethoxylates of soya bean oil towards the corrosion of zinc in 2M H2SO4 using

thermometric methods. The results show that the retardation of metal dissolution

is due to chemisorption.

Karthikeyan et al52 have studied the influence of anions such as chlorides

and sulphates in the performance of thiomalic acid as an inhibitor for the

corrosion of mild steel in HCl and H2SO4 and in their studies they have reported

that thiomalic acid brings down the hydrogen permeation through mild steel in

both acids. Milan Bartus et al53 have investigated the corrosion inhibition of mild

steel in CO2 saturated synthetic brine by low molecular weight organic acids

containing sulphur in their molecular structure such as thioglycollic acid.

Phosphonates terminated carboxylate –based telomers have been used as

scale/corrosion inhibitors and /or fouling agents in aqueous system54. Corrosion

inhibition of carbon steel by 2-phosphonobutane-1,2,4-tricarboxylic acid is based

on the formation of an inhibiting film.55

It has been reported that corrosion of carbon steel can be inhibited by the

addition of organic phosphono carboxylic acid (e.g., 2-phosphonobutane-1, 2,4-

tricarboxylic acid and/or phosphino carboxylic acid and manganese56. Corrosion

inhibiting compositions containing carboxylated phosphonic acid (hydroxy

33

phosphonoacetic acid or 2- phosphonobutane- 1, 2,4-tricarboxylic acid) and a

sequesterant selected from tartaric acid, citric acid, and gluconic acid have been

studied57.

A corrosion inhibitor for iron based alloys in an aqueous system (tap water)

comprises of hydroxy phosphonoacetic acid or its water soluble ammonium or

alkali metal salt and co-polymer formed from 2-acrylamido-2-methylpropane

sulphonic acid and acrylic acid or methacryllic acid has been developed.58

Aramaki59, 60 has reported that the film of 1, 2-bis(triethoxysilyl)ether polymer

containing sodium octylthiopropionate (NaOTP) prevented corrosion of iron at

scratched surface in aerated NaCl solutions. X-ray, photo electron spectroscopy

and electron probe micro analysis of the surface have revealed that the corrosion

at scratch was suppressed by the formation of iron oxide layer containing a small

amount of complex formed by NaOTP with Fe3+.

Malik61 has investigated the effect of pH on the performance of tertiary

amines possessing a single carboxylic acid group for the corrosion of mild steel

in CO2 saturated brine solution. It is reported that at pH 6.5, the inhibition is

primarily due to the attachment of O- at anodic site while at pH 3.9, corrosion

rate decreases as a result of the inhibitor loosely lying flat at the metal solution

interface. Malik62 has reported that negatively charged species exhibit better

inhibition efficiencies at pH 6.5 while positively charged species show better

inhibition efficiencies at pH 3.9.

According to Kunitsugu Aramaki63 the inhibition effect of organic

inhibitors such as sodium benzoate, sodium N-dodecanoyl sarcosinate, sodium

S-octyl-3-thiopropionate and 1,2,3-benzotriazole are due to the formation of film

containing zinc salts or complexes together with Zn(OH)2.The film was analysed

by X-ray, photoelectron and Fourier transform infrared reflection spectroscopy.

Sakthivel et al64 have evaluated the corrosion inhibition properties of ethyl-1,2-

N-diphsophonomethylamino diethanoic acid for mild steel in cooling water.

34

Based on gravimetric, cathodic Tafel plots, linear polarization resistance and EIS

methods, Chetouani et al65 have concluded that the inhibiting effects of

N,N-bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-N-(4-methylphenyl)amine (P1)

and methyl-1-[((methylphenyl){[3-(methoxycarbonyl)-5-methyl-1H-pyrazole-1-

yl] methyl} amino)methyl]-5-methyl-1H-pyrazole-3-carboxylate (P2) on

corrosion of pure iron in 1M HCl are due to adsorption of the inhibitor on the

metal surface which obeys Langmuir adsorption isotherm and they act as mixed

inhibitors.

Nathalie et al66 have reported that the inhibition efficiency of the inhibitor

system consisting of fatty amines and phosphonocarboxylic acid salts are due to

the formation of the chelates between the phosphonocarboxylic acid salts and Fe

oxide / hydroxide.

II.4. Simple Aromatic carboxylic acids and their derivatives as corrosion inhibitors :

Bilgic67 has reported that benzoic acid acts as a better inhibitor for the

corrosion of steel in sulphuric acid, compared to salicylic acid with the same

concentration. Both the inhibitors obey Langmuir isotherm. Maria Forsyth et al68

have established the existence of synergism between Ce3+ ion and salicylate

anion, in their study on corrosion inhibition of mild steel surfaces by cerium

salicylate. Blustein et al69,70 have proposed adsorption mechanism for the

inhibitive properties of calcium benzoate for steel corrosion in NaNO3 solutions.

Faidi and Scantlebury71 have studied the corrosion behaviour of mild steel in

single-phase glycol–ether-water mixture on the addition of NaNO2, sodium

benzoate and benzylamine.

Turgoose72 in his article on the influence of sodium benzoate on corrosion

of steel has concluded that too low or too high content of benzoate leads to

corrosion. The influence of aggressive ions on the corrosion of iron in the

presence of benzoate anion has been reported73-86

35

The effects of polyhydroxy carboxylates, and benzoate on pitting corrosion

of steel were studied using cyclic anodic polarization measurements in chloride

solutions.87 Fouda et al88 have studied the effects of phthalimide derivatives on

the corrosion behaviour of Cu in nitric acid.

The inhibitive action of benzoic acid and its derivatives on dissolution of

Al89and Cu90 in HNO3 is studied by Agrawal et al. Moussa et al91 have explained

that the inhibition efficiency of aromatic acids depends on the number and

position of the carboxylic group and other substituents in the benzene ring;

Inhibition efficiency is higher in NaOH than HCl. For aliphatic carboxylic acids,

the increase in chain length increases the inhibitive power. Fokin et al92 have

related the effect of the structural parameters of aliphatic and aromatic carboxylic

acids, dicarboxylic acids, their anhydrides, imides and nitro compounds on their

inhibition efficiency for the corrosion of steel in hydrocarbon /electrolyte system.

According to Dinnappa and Mayanna93 the corrosion inhibition of benzoic

acid, p-toluic acid, p-nitro benzoic acid and terephthalic acid for Cu in perchloric

acid is due to the adsorption of inhibitor molecules at the metal –solution

interface. Bilgic and Yilmaz94 have reported that the inhibition efficiency of

benzoic acid for steel corrosion in 0.5 M H2SO4 was found to increase by the

addition of NaCl, NaBr and NaI. However potassium salts of the same halides

are less effective than sodium salts.

Based on ATR and FTIR spectra, Frederic et al95 have explained that the

protection mechanism of cerium and lanthanum cinnamate based corrosion

inhibitors on the corrosion of steel in neutral chloride solution is due to the

adsorption of the rare earth metal cinnamate complex followed by the hydrolysis

of the REM (Rare Earth Metal) to form a barrier oxide on the steel surface.

Abd -El Kadher et al96 have evaluated the corrosion inhibition effect of sodium

benzoate, calcium gluconate and sodium glycerophosphate as co-inhibitors with

sodium tungstate in distilled water and in 10-3 M NaCl. Tungstate –carboxylate

36

combinations have also been reported for corrosion and scale inhibition.97 A

volatile rust prevention paper has been developed based on the synergistic effect

of tungstate, hexamine and sodium benzoate, which can be used in rust

prevention of steel, Al and Cu etc.98

Nagaraju et al99 have studied the corrosion inhibition of potassium

hydrogen phthalate, phthalic acid and salicylic acid on the corrosion of brass in

sulphuric acid. Bilgic and Sahin 100 have investigated the corrosion inhibition of

steel by salicylic acid in acid media. A new inhibitor formulation with synergistic

property containing cinnamate and substituted cinnamate with rare earth metals

has been designed and they have been noted to perform better than benzoate

anion.101

Granata et al102 have studied the inhibitive action of many aromatic and

aliphatic monocarboxylates and reported that carboxylates, oxidants and

controlled pH yields corrosion free environment for steel in chloride containing

aqueous solutions. Cinnamylidene acetate provides excellent protection for steel

for a long period and it also controls crevice corrosion.

Stefanova 103 has studied the inhibitor and biocidal efficiency of three

chemical compounds – potassium permanganate, sodium benzoate and

cetylpyridinium bromide (CPB) as additives to cooling water systems for

corrosion protection of the metal equipment and against microbiological

contamination. Phthalic anhydride, ATMP, zinc ions as a three components

inhibitor has good adsorption and corrosion inhibiting properties.104 Adsorption

of bromine labelled aromatic carboxylic acid corrosion inhibitor on iron

polarized in the active region was studied with EQCM, EIS and XPS.105

Pavlovi et al106 have studied the effect of benzoic acid on the corrosion and

stabilization of electrodeposited copper powder. Eurof Davies and Slaiman107

have discussed the role of dissolved oxygen in decreasing the corrosion of iron

by the inhibitor sodium benzoate.

37

II.5. Aliphatic Monocarboxylic acids and their Derivatives as corrosion inhibitors :

Szauer and Brandt108 have related the inhibition efficiency of amines and

fatty acids for iron

with the amount of complexes formed

on the spatial and chemical structure of individual compounds and their

complexes

the adsorption forces involved and

the interaction within the adsorption layer.

Lykov et al109 have reported that synthetic unsaturated fatty acids give good

corrosion protection to carbon steel in jet fuels. Rocca and Steinmetz110 have

evaluated the inhibition efficiency of sodium mono carboxylates in aqueous

solutions for Pb using electrochemical methods and have shown that the longest

carbon chain provides maximum efficiency and inhibition due to passivation of

metals. Szauer has investigated the inhibition efficiency of salts of amines and

unsaturated fatty acids present in organic coatings in acid111 and neutral media.112

Lahodney and Popov113 have examined the inhibitive action of sodium

gluconate and sodium tetra borate on mild steel using potentiodynamic

polarization and weight –loss measurements and reported that the role of sodium

tetra borate is to stabilize the protective film formed on the surface of mild steel.

According to Szauer and Brandt114 the corrosion inhibition of iron by

triethylamine salts of 18C unsaturated fatty acids in 0.5M deaerated H2SO4

solutions is due to the preferential adsorption of fatty acids on the metal surface.

The main role of amine is to cross-link the acid chains adsorbed on the iron

surface.

Reinaldo Sim es Goncalves et al115 have studied the inhibitive action of

acetate ions for the corrosion processes of low carbon steel in hydrated ethanol

38

by potentiodynamic, conductance and mass-loss measurements and reported that

the anodic oxidation of electrode decreases with increase in the concentration of

acetate ions. Singh and Singh116 have reported that copper metal exhibited active

passive behaviour in the concentration range of 30-70 mol/o of acetic acid in the

solution mixture containing both formic and acetic acid.

II.6. Aliphatic Di and Tricarboxylic acids as corrosion inhibitors :

Gunasekaran et al117 have established the synergistic effect of tartrate with

organophosphonic acid and zinc metal ions in neutral environment on the

corrosion inhibition of steel. Muthumani et al118 have examined the inhibition

efficiency of sodium potassium tartrate in controlling the corrosion of carbon

steel immersed in ground water in the absence and presence of Zn2+. According

to Baah & Baah119 the inhibition effect of oxalic acid on the corrosion of Cu in

concentrated propionic acid and dil.citric acid is due to the formation of oxide

layer on the surface of the sample. Shao et al120 reported that calcium ions form

complex with tartrate ions and this complex acts as interface inhibitor for the

corrosion of Al in an alkaline solution. Almeida and Giannetti121 have examined

the protective film growth on tin in perchlorate and citric acid and reported that

pitting inhibition may be due to the formation of the mixed layer of tin oxide and

tin-citrate complex on the electrode surface.

Muller et al122 have reported that soluble zinc (II) Al(III) or cerium (III)

chelates of citric acid exhibits excellent inhibiting effect for zinc pigments in

aqueous alkaline media.

Singh and Archana123, 124 have studied the corrosion characteristics of Al

alloys in oxalic acid. Giacomelli et al125 have reported that oxalic acid is found to

be a good corrosion inhibitor for carbon steel in acid medium for pH greater than

3. Mercer and William126 have compared the corrosion inhibition of aliphatic

dibasic acid such as 1,10-decanedioic acid and mono basic acid such as octanoic

acid with the traditional inhibitor like benzoic acid in automotive cooling systems

39

According to Giacomelli et al127 the inhibitive effect of succinic acid on the

corrosion resistance of mild steel is due to the decrease in the anodic and

cathodic reactions up to pH 3. Above pH 4, no inhibitive effect is observed.

Sagoe et al128 have studied the corrosion inhibition of steel in concrete by

malonic acid. The study report of Spathis et al129 on the corrosion and stress

corrosion cracking behavior of Al alloy in acid medium, in the presence of

various carboxylic acids (saturated or not, with different number of carboxylic,

methyl or hydroxyl groups) has revealed that

Malonic acid exhibits better protective property due to adsorption on the

metal surface,

Saturated dicarboxylic acid provides better protection against stress

cracking corrosion,

The presence of methyl group improves the protective property of the

oxide.

Muller130 has reported that the corrosion inhibition of Al pigment in

aqueous alkaline medium by citric acid is due to the

i) Formation of aluminium- citrate complex

ii) Agaric acid, a surfactant inhibits the corrosion of Al pigments better

than citric acid. Abd El- Maksoud et al131 have examined the electrochemical

behaviour of carbon steel in a wide range of concentration of gluconate and

tartrate by potentiodynamic and open circuit measurements and reported that

corrosivity of carbon steel in tartrate is higher than in gluconate. Pemberton

et al132 have observed a synergistic effect between sodium sebaccate and

benzotriazole for the corrosion inhibition of cast iron, galvanized steel and mild

steel in distilled water and dilute salt solutions.

40

Butler and Mercer133 have reported that disodium sebaccate when used with

benzotriazole provides effective inhibition of the corrosion of carbon steel, cast

iron, Al alloy, Pb and tin solder, Cu and brass in engine coolants containing 50%

ethanediol. Beale et al134 have evaluated a novel engine coolant formulations

containing ethanediol, disodium sebaccate and benzotriazole. John Amal Raj et

al135,136 have reported the influence of dihydroxy dicarboxylic acid on the

inhibition efficiency of a phophonate-Zn2+ system in controlling the corrosion of

carbon steel in an aqueous environment containing Cl- ion. Thangavelu et al137

have evaluated the synergistic effect of citrate and Zn2+ on the corrosion of

carbon in dil. salt solutions.

Dong-Jin Choi et al138 have reported that the new all-organic

multicomponent inhibitor blend composed of citric acid/phosphonates/acrylate

copolymer/ isothiazolone effectively decreases the corrosion, scale built up and

microbial growth for carbon steel in open recirculating cooling water system. It is

reported that the inhibition effect are due to the formation of a protective film.

Ruba Helen Florence et al139 have studied the corrosion inhibition of carbon steel

in ground water by adipic acid and Zn2+ system.

Felicia Rajammal Selvarani et al140 have reported the existence of

synergism between succinic acid and Zn2+ in controlling the corrosion of carbon

steel in well water. Arichandran et al141 have reported that the protective film

formed on the carbon steel immersed in well water containing citrate-Zn2+ system

consists of iron –citrate complex and Zn(OH)2.Vigant et al142 have observed that

alkenyl succinic acid, calcium alkyl benzolsulphonate, urea and alkyl

succinimide replaces , displaces HBr, HCl, H2SO4 and acetic acid which are

found on the surface of the steel in industrial and sea atmospheres and provide

protection due to chemical or physical adsorption.

The influence of the inhibitive system consisting of ATMP, oxalic acid or

phthalic anhydride and zinc sulphate on the rate of corrosion of steel in simulated

41

industrial water of variable chemical composition and in water being chlorinated

has been studied by gravimetric method. This formulation is considered as a

perspective inhibitor for the corrosion protection of industrial cooling and heating

water installation.143 Kubicki et al144 have investigated the inhibitive property of

amino(trimethylene phosphoric acid) (ATMP) in preventing the corrosion of iron

in neutral , aqueous solution in combination with carboxylic acid and Zn2+ salts .

Greatest protective effectiveness was obtained for tricomponent composition

containing ATMP, phthalic acid or oxalic acid and Zn2+. Sodium dodecyl

succinate and sodium nitrite show synergistic effect in controlling the corrosion

of steel in simulated cooling water circulates145

II.7. Zinc ions as corrosion inhibitors:

Zinc ions have long been considered as valuable corrosion inhibitors for

carbon steel in aerated water because of the protection afforded by a cathodic

polarization mechanism.146,147 However due to the problem of toxicity of Zn2+

ions ,it is necessary to reduce the concentration of Zn2+ by introducing a synergist

which is environmentally friendly. Several organic inhibitors were evaluated as

excellent co-inhibitors with Zn2+ for carbon steel substrate. According to Pech

and Bartolo19 the inhibitive effect of N-phosphonomethyl glycine-Zn2+ mixture

on corrosion of steel in neutral medium is due to the retardation of anodic and

cathodic process due to the film Fe- inhibitor complex and ZnO. Amino

carboxylic acids and their N-phosphonomethyl derivatives with or without

additives (Zn or metavanadate ion) have been studied in neutral solution by

Kalman et al.22

Gunasekaran et al117 have established the synergistic effect of tartrate with

organophosphonic acid and zinc metal ions in neutral environment on the

corrosion of steel. Muthumani et al118 have examined the inhibition efficiency of

sodium potassium tartrate in controlling the corrosion of carbon steel immersed

in ground water in the absence and presence of Zn2+. John Amal Raj et al135,136

42

have reported the synergistic effect of dihydroxy dicarboxylic acid on the

inhibition efficiency of a phophonate-Zn2+ system in controlling the corrosion of

carbon steel in an aqueous environment containing Cl- ion.

Thangavelu et al137 have evaluated the synergistic effect of citrate and Zn2+

on the corrosion of carbon in dil.salt solutions. Ruba Helen Florence et al139 have

studied the corrosion inhibition of carbon steel in groundwater by adipic acid and

Zn2+ system. Felicia Rajammal Selvarani et al140 have reported the existence of

synergism between Succinic acid and Zn2+ in controlling corrosion of carbon

steel in well water. Aarichandran et al141 have reported that the protective film

formed on the carbon steel immersed in well water containing citrate-Zn2+ system

consists of iron –citrate complex and Zn(OH)2.The influence of the inhibitive

system consisting of ATMP, oxalic acid or phthalic anhydride and zinc sulphate

on the rate of corrosion of steel in simulated industrial water of variable chemical

composition and in water being chlorinated has been studied by gravimetric

method. This formulation is considered as a perspective inhibitor for the

corrosion protection of industrial cooling and heating water installation.143

Kubicki et al 144 have investigated the inhibitive property of amino(trimethylene

phosphoric acid) (ATMP) in preventing the corrosion of iron in neutral , aqueous

solution in combination with carboxylic acid and Zn2+ salts . Greatest protective

effectiveness was obtained for tricomponent composition containing ATMP,

phthalic acid or oxalic acid and Zn2+. Susai Rajendran et al have studied the role

of Zn2+ in the inhibition of corrosion of mild steel in neutral, aqueous

environment, containing 60 ppm of Cl- by the inhibitors-molybdate, 148 HEDP149

and HEDP-molybdate.150 Rajendran et al151 have reported that

phenylphosphonate acts synergistically with low concentration of Zn2+ in

inhibiting the corrosion of mild steel in a neutral aqueous chloride environment .

However at higher concentrations of Zn2+ decrease in inhibition efficiency is

observed due to the formation of a insoluble Zn2+ -PPA complex The presence of

Zn2+ions facilitate the transport of these inhibitors from the bulk to the metal

43

surface. Both cathodic and anodic reactions are controlled. Corrosion of iron-

based alloys in a circulating water is decreased by a synergistic inhibitor mixture

containing HEDP, hydroxy phosphonoacetic acid and sodium tolyltriazole 152

2-phosphonobutane-1, 2,4-tricarboxylic acid (pBTCA) shows synergistic effect

with Zn2+ ions153 , Zn2+-HEDP combination 154 and MnCl2.4H2O56. When

pBTCA is used along with Zn2+ in the corrosion inhibition of mild steel in tap

water, Zn(Ca)-PBTCA-Fe(III) sequestering film deposited on the surface of mild

steel inhibits corrosion effectively.153

Yang Zhang et al155 have reported that iminodimethylene phosphonic acid

when used in combination with Zn2+ and polyacrylate shows synergistic effect

and act as multifunctional inhibitor for cooling water. Venugopalan et al156 have

developed the inhibitor formulation consisting of zinc ions, HEDP and an organic

additive zinc gluconate for corrosion inhibition of mild steel in neutral aqueous

medium containing 60 ppm of Cl- ions. It is reported that it acts as a mixed

inhibitor. Complexes of HEDP and gluconate ions and Zn(OH)2 were found on

the metal surface.

Studies on ascorbate as second synergist along with Zn2+ and phosphonates

in the corrosion inhibition of carbon steel in low chloride environment were

reported by Apparao and Srinivas Rao157. Wrubl et al 158 have appraised the

efficiency of Zn basic gluconate as a corrosion inhibitor for mild steel in sodium

chloride solution. According to them, the inhibition is due to Zn2+ ions, Zn

(C6H11O7)+ and (C6H11O7)

- ion. Susai Rajendran et al159 have reported the

synergistic and antagonistic effect existing among polyacrylamide, phenyl

phosphonates and Zn2+ on the inhibition of corrosion of mild steel in an aqueous

neutral environment. Meena et al160, 161 have investigated the influence of Zn2+ on

the corrosion rate of carbon steel immersed in an aqueous environment

containing 60 ppm of Cl- and carboxymethyl cellulose (CMC). A synergistic

effect is noticed between CMC and Zn2+. Manjula et al162 have studied the

corrosion behavior of carbon steel in aqueous medium in the presence of

44

N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) , Zn2+ and calcium

gluconate.

The existence of synergism between molybdate and Zn2+ ions has been

reported163-166. Corrosion inhibition efficiency of HEDP synergistically was

improved by adding Zn2+ions165,167-169. The synergistic effect of Zn2+and HEDP

in decreasing the corrosion rates of steel in seawater was observed 168. The

protective cathodic film on the steel consists of Mg (predominant), P and Zn.

Gonzales et al170 have carried out electrochemical measurements and used

analytical techniques (XPS, Reflection absorption spectroscopy) to investigate

the inhibition of corrosion of carbon steel by a mixture of zinc salt and

phosphonic acid. They have reported the formation of a homogeneous thin film

on the surface of the metal.

II.8.Biocides

Cooling water systems are extremely vulnerable to microbial

contamination. Problems occur when microbes begin to proliferate and attach to

system surfaces. For example, in the case of cooling coil systems microbes can

easily congest the system, restricting water flow and ultimately, reduce heat

exchange. The result is increased operating costs in the form of poor heat

dissipation, overall system inefficiency, and system clean up, including any

downtime that may be necessary. Corrosion can also result from unchecked

microbial growth. Microorganisms such as bacteria, fungi and algae can combine

with organic compounds to form biofilms. The microbes in these films produce

products of metabolism that are corrosive in nature. The result is pitting and

corrosion of metal components. Wooden system support structures are also

vulnerable, as wood-destroying fungi can cause significant damage as well.

45

To eliminate the threat of such potential problems and achieve optimum

system efficiency, microbiological activity within a system must be properly

controlled. Though a seemingly straightforward goal, cost concerns, system

operating guidelines, and additive compatibility all greatly influence treatment

choice. Environmental, health and safety considerations also have a great impact.

To be considered a viable option, a biocide must successfully control a broad

spectrum of microbial contamination, provide cost-effective performance and

prove compatible with other system components, while at the same time meeting

stringent environmental, health and safety standards. Literature survey has shown

a number of biocides which were used along with corrosion inhibitors.

Ramesh et al171 have investigated the inhibition efficiency of

triazolephosphonates compounds namely 3-benzyledene-amino-1,2,4-

triazolephosphonates, 3-cinnamyledene-amino-1,2,4-triazolephosphonates and

3-anisalidene-amino-1,2,4-triazolephosphonates,along with biocide action on

corrosion of mild steel. They have also evaluated the biocidal action of the

inhibitors on the corrosion control of Cu172 in neutral aqueous environment.

Stefanova103 has studied the biocidal efficiency of cetylpyridinium bromide,

(CPB), potassium permanganate and sodium benzoate. He has reported that the

CPB has a wide range of effect for microorganisms typical for water media. Its

high biocide efficiency is a prerequisite for its use as additive to cooling water.

Sodium benzoate and potassium permanganate acts selectively to particular

representative of the microorganism’s characteristic for the water media.

Dong-Jin Choi et al138 have reported that the new all-organic inhibitor blend

composed of citric acid/phosphonates/acrylate copolymer/ isothiazolone

effectively decreases the corrosion, scale built up and microbial growth for

carbon steel in open recirculating cooling water system. It is reported that the

inhibition effect are due to the formation of a protective film. Rajendran

et al 173-175 have studied the influence of biocide on corrosion inhibition of mild

steel by ATMP-Zn2+ system. The formulation consisting of 200 ppm of ATMP,

46

100 ppm CTAB has shown 99% corrosion inhibition efficiency and 100%

biocidal efficiency. It is reported that CTAB acts as an excellent biocide as

monomer and also as micelle176. Bernard et al177 have evaluated the bacterial

efficiencies of the four bacteriocides – organosulphur, mixed aldehyde-organo

sulphur, mixed aldehyde-quaternary ammonium and organo brome compounds

on the polluted water from sulphuric acid manufacturing plants. Manimegalai et

al178 have examined the inhibitive property as well as the biocidal properties of

the leaf extracts of Azadiracta Indica and reported that the inhibitor has very

effective biocidal property as well as inhibitive property for mild steel in fresh

water environment. It is reported that most of the biofilms are sensitive to the

detergent biocide SDS179,180.

Iwalokun et al181 have suggested to use urea and SDS in the laboratory to

reduce the risk of infection with virulent proteus strains. Richard et al182 have

investigated the effect of the surfactants alcohol ethoxylates, amine ethoxylates,

amine oxide and SDS on bacterial cell membranes using EPR spectroscopy.

Lin et al 183 have reported that CPC a quaternary ammonium salt and a

cationic surfactant has been used as a biocide in personal hygiene products. It is

reported that CPC acts as an antifungal agent,184 and as a biocide251 for

cosmetics, toiletries and pharmaceuticals activity.

II.9. Biocides as corrosion inhibitors:

The major problems in industrial use of the cooling water system are

corrosion of the metal equipment, contamination of the circulating water system

with microorganisms, and deposit formation that worsens the heat exchange. To

solve the above problems complex treatment of the water is required including

the use of the metal corrosion and antideposit additives. In view of the large

water losses in the systems resulting from evaporation and leakages, the

application of these chemicals, which are economically expedient, if they behave

efficiently at low concentrations are sought. The compatibility of the different

47

additives in the system also matters as very often a good biocide exhibits strong

corrosion effect on the metal equipment and reduces the effect of inhibitors used,

that is why it is of interest to find out chemical compounds which when added to

water will have more than one function or at least will not negatively affect the

action of the other additives.

Many surfactants function as biocides. Several surfactants have also been

used as corrosion inhibitors.186-190 Review of literature reveals that sodium

dodecyl sulphate and many quaternary ammonium salts such as CTAB and CPC

functions as excellent corrosion inhibitors in different environment for various

metals. According to Bereket and Yurt191 quaternary ammonium salts behave as

mixed inhibitors on the corrosion of low carbon steel in acidic solutions and the

inhibition efficiency is maximum around and above the critical micellar

concentrations.

The studies on the corrosion inhibition of iron in acidic solutions by alkyl

quaternary ammonium halides by Lin Niu et al192 reveal that the structure of

alkyl group and the type of halide ions of these inhibitors greatly influence the

inhibition efficiency. Saeed and Ali193 have synthesized a variety of

bisquaternary ammonium salts and they exhibit excellent inhibition for the

corrosion of carbon steel. Bernard et al194 have reported that the inhibition

efficiency increases with increase in the polar head group size and also the length

of the carbon chain of quaternary ammonium salts due to the formation of a close

packed layer. According to Hoar and Holliday195, the inhibiting action of CTAB

is due to the adsorption of cetyl ammonium cations on the most active anodic

sites, which interfere with the anodic reactions by hindering the escape of Fe2+

ions from the metal surface into the solution. Rajendran et al have investigated

the influence of the cationic surfactant N-cetyl,N,N,N-trimethyl ammonium

bromide (CTAB) on the Zn2+-ATMP174, Zn2+-HEDP175 and the calcium

gluconate-Zn2+ 196 in controlling the corrosion of carbon steel in aqueous

environment. Manjula et al 197 have studied the corrosion behaviour of carbon

48

steel in the presence of N-cetyl, N,N,N-trimethylammonium bromide , Zn2+ and

calcium gluconate. Houyi Ma et al198 have investigated the inhibitive action of

CTAB, SDS, sodium oleate and polyoxyethylene sorbitan monooleate on the

corrosion behaviour of Cu by electron impedance spectroscopy. CTAB was

found to be the most efficient inhibitor due to the synergistic effect between

bromide anions and the positive quaternary ammonium ions. Karpagavalli and

Rajeswari199 have reported the application of CTAB as inhibitor for the corrosion

of brass in ground water. Soror and El-Ziady 200 have studied the effect of CTAB

on the corrosion of carbon steel in acid. Lalitha et al201 have shown the existence

of synergistic effect between SDS, CTAB with triazoles for the corrosion

inhibitions of copper in acid medium. Michael.L.Free202 has related the corrosion

inhibition of mild steel in acidic medium by surfactant molecules cetyl

pyridinium chloride and cetyltrimethylammonium bromide to the surfactant’s

ability to aggregate at interfaces and in solution. Lin Wang et al203 have shown

that both 2-mercaptothiazoline and cetylpyridinium chloride functions as

effective inhibitors for low carbon steel over a wide concentration range of

aqueous phosphoric acid solution.

According to Abd-El-Maksoud 204 hexadecylpyridinium bromide and

hexadecyltrimethyl ammonium bromide, act as mixed inhibitors for iron and Cu

in HCl and H2SO4 due to the potential of the zero charge of the metal and due to

the adsorption ability of chloride and sulfate ions on the metal surfaces.

Suguna et al205 have determined the corrosion rates of carbon steel in the

absence and presence of sodium dodecyl sulfate and Zn2+ in aqueous solutions.

Rong Guo et al206 have studied the effects of sodium dodecyl sulphate (SDS) and

some alcohols (ethanol/n-butanol) on the inhibition of the corrosion of Ni.

Abd-El-Rehim et al207 have reported that the inhibition of corrosion of Al alloy in

1 M HCl in the temperature range 10-60 C occurs through the adsorption of the

anionic surfactant SDS on the metal surface without modifying the mechanism of

the corrosion process. The effect of SDS and Cu corrosion has been studied in

49

the absence and presence of benzotriazole using electrochemical impedance and

surface tension measurements.208, 209 Susai Rajendran et al210 have evaluated the

inhibition efficiency of SDS in controlling the corrosion of carbon steel

immersed in 60 ppm of NaCl in the absence and presence of Zn2+. FTIR

spectrum has revealed the presence of a film containing iron-SDS complex and

Zn(OH)2.

Monticelli et al211 have investigated the corrosion inhibition of Al alloy

(AA 6351) in 0.01 M NaCl using inhibitors such as sodium salts of

N-dodecanoyl-N-methylglycine (NLS), dodecyl sulfate (LS), N-dodecanoyl-N-

methyltaurine (NLT) and dodecylbenzene sulfonate (DBS).

The existence of synergism and antagonism in mild steel corrosion

inhibition by sodium dodecylbenzene sulfonate and hexamethylenetetramine has

been ascribed to the formation of hemi-micellar aggregation that provoke

inhibitor desorption from the metal/solution interface at higher concentration.212

Susai Rajendran et al213 have reported the mutual influence of HEDP and

SDS on the corrosion inhibition of carbon steel immersed in rain water in the

presence of Zn2+. Rajendran et al214 have studied the influence of sodium sulfate,

SDS, pH and duration of immersion on the inhibition efficiency of polyvinyl

alcohol –Zn2+ system. They have noted the existence of synergistic effect

between PVA-Zn2+ and SDS

The literature survey suggests that corrosion inhibitors based on carboxylic

acids remain a fruitful field of investigation. Literature survey also clearly has

shown the importance of Zn2+ ions as corrosion inhibitor. Zn2+ was also

successfully employed as a co-inhibitor with many organic inhibitors. In this

context, the objective of the present set of studies was framed to investigate in

detail, the mutual influence of Zn2+ and few dicarboxylic acids using different

techniques under different experimental conditions and the compatibility of the

inhibitor systems with few biocides.

50

II.10.BIBLIOGRAPHY

1. E.V. Bogatyreva and S.A. Balezin, Zh Prikl Khim, 32 (1959)1071.

2. E.V. Bogatyreva and V.V. Nagaev, Zh Prikl Khim, 35 (1962)556.

3. E.V. Bogatyreva, Khim Khim Tekhnol (1) (1959)

4. Yu.I. Kuznetsov, S.V. Oleynik, N.N.Andreev and S.S.Vesely, Sixth

European Symposium on Corrosion Inhibitors, Ferrara, Italy, 1(8) (1985)

567.

5. E.V. Bogatyreva and M.A.Karepina, Zh Prikl Khim, 36 (1963)147.

6. N.G. Klyuchnikov and N.S. Novoshinskaya, Zh Prikl Khim, 36 (1963)2470

7. W.Funke and K.Hamann, Werkst Korros, 9 (1958) 202

8. I.L. Rosenfeld, Yu.I.Kuznetsov, I.Ya. Kerbeleva, V.P.Persianceva, Prot.

Met. 10 (1974) 612.

9. M.Fisher, Z Phys.Chem (Leipzig) 260 (1979)93.

10. J.G.N.Thomas, Proceedings of the Fifth European Symposium on

Corrosion Inhibitors, Ferrara, Italy, 2 (1980) 453.

11. Chemistry research for the years 1958, 1951 and 1954 Published by

HMSO, London.

12. P. Hersch, J Appl Chem, 11 (1961)246.

13. J.E.O. Mayne and E.M.Ramshaw J.Appl Chem., 10 (1980) 419.

14. N.K.Shmeleva and V.P.Barannik, Zh Prikl Khim, 36 (1963) 813.

51

15. A.D.Mercer, Proc. of Fifth Conf. on Corrosion Inhibitors, Ferrara, Italy,

(7) (1980) 563

16. G.Bereket and A.Yurt, Corrosion Science, 43(6) June (2001) 1179-1195.

17. A.Yurt, G.Bereket and C.Ogretir, Journal of Molecular Structure:

Theochem, 725 (1-3) 11 July (2005) 215-221.

18. A.A.Aksut and S.Bilgic, Corrosion Science, 33 (3) March (1992)379-387.

19. M.A.Pech-Canul and P.Bartolo-Perez, Surface and Coatings Technology,

184 (2-3) 22 June (2004)133-140.

20. M.Zerfaoui, H. Oudda, B.Hammouti, S.Kertit and M.Benkaddour, Progress

in Organic Coatings, 51 (2) Nov.(2004) 134-138.

21. B.A.Abd-El-Nabey, N.Khalil and A.Mohamed, Surface Technology, 24 (4)

April (1985) 383-389.

22. E.Kalman. F.H.Karman, J,Telegdi, B.Varhegyi, J.Balla and T.Kiss,

Corrosion Science, 35 (5-8) (1993) 1477-1482.

23. H.Ashassi-Sorkhabi, M.R.Majidi and K.Seyyedi, Applied Surface Science,

225 (1-4) 30 Mar. (2004) 176-185.

24. H.Ashassi-Sorkhabi, Z.Ghasemi and D.Seifzadeh, Applied Surface Science

249 (1-4) 15 Aug.(2005) 408- 418.

25. Gamal K.Gomma and Mostaf H.Wahdan, Materials Chemistry and Physics,

39 (2) Dec. (1994) 142-148.

26. S.Rajendran, B.V.Apparao and N.Palaniswamy, Anti-Corrosion methods

and Materials, 46(2) (1999) 111-116.

27. K.Aramaki, Corrosion, 56(9) (2000) 901-909.

52

28. M.Yuasa, T.Oshibe, T.Iahii, A.Suzuki, T.Aizawa, H.Yajima, K.Akiyama

and Y,Sekshibata; Hyomen Gijutsu, 50(12), (1999) 1147-1152.

29. M.Yuasa, M.Morooka, N.Ishida, N.Kawamura, I.Sekine, T.Wake,

T.Imahama, H.Murata and Y.Shibata, Hyomen Gijutsu, 51(11) (2000)

1148-1153.

30. Bodo Muller, Ileana Forster and Wolfgang Klager, Progress in Organic

Coatings, 31 (3) 27 Nov (1997) 229-233.

31. S.S Abd El Rehim, F.M.Tohamy and M.M.Seleet, Surface Technology, 21

(2) Feb. (1984)169-177.

32. D.Yamamoto and Suzuki, Proc. Fourth Euro. Symp. on Corrosion

.Inhibitors, Ferrara, Italy, 1(1975) 274.

33. T.Suzuki,S.Kubo, H.Morinaga and T.Tsuneki, Proc, Seventh

Euro.Symp.on Corrosion Inhibitors, Ferrara, Italy, 1(1990) 503.

34. Bodo Muller, Reactive and Functional Polymers 39 (2) 15 Feb. (1999)165-

177.

35. I.Sekine, M.Sanbongi, H.Hagiuda, T.Oshibe, M.Yuasa, T. Imahama,

Y.Shibata and T.Wake, Journal of the Electrochemical Society, 139 (11)

Nov.(1992) 3167-3173.

36. P.Shah, S.K.Shukla, A.N.Misra and D.C.Pater, Research and Industry,

36(1991)105.

37. Nathalie Ochoa, Francis Moran, Nadine Pebere and Bernard Tribollet,

Corrosion Science, 47 (3) March (2005) 593-604.

38. M.Zerfaoui, H.Oudda, B.Hammouti, M.Benkaddour, S.Kertit, M.Zertoubi,

M.Azzi and M.Taleb Rev.Met Paris, (12) Dec.(2002) 1105-1110.

53

39. R.G.Aitov, A.B.Shein, A.E.Lesnov and A.V.Radushev, Zashchita Metallov,

30(5) Sep-Oct (1994) 548-549.

40. M.M Osman and M.N.Shalaby, Materials Chemistry and Physics, 77 (1) 2nd

Jan.(2003) 261-269.

41. E.E Foad El-Sherbini, S.M.Abdel Wahaab and M.Deyab, Materials

Chemistry and Physics, 89 (2-3) 15 Feb.(2005) 183-191.

42. M.M.Osman and S.S. Abad El Rehim, Materials Chemistry and Physics, 53

(1) April (1998) 34-40.

43. E.E Foad El Sherbini, Materials Chemistry and Physics, 60 (3)15 Sep

(1999) 286-290.

44. M.A.Quraishi and Danish Jamal, Materials Chemistry and Physics, 71 (2)

15 Aug (2001) 202-205.

45. M.Bouklah, A.Quassini, B. Hammouti. and A.El.Idrissi, Applied Surface

Science, 250 (1-4) 31Aug.(2005) 50-56.

46. M.Bouklah, A.Attayibat, S.Kertit, A.Ramdani and B.Hammouti, Applied

Surface Science, 242 (3-4) 15 Apr. (2005)399-406.

47. P.Agarwal and D.Landolt, Corrosion Science, 40 (4-5) Apr-May (1998)

673-691.

48. A.V.Radushev, A.B.Shein, R.G.Antov, V.Yu Gusev, N.F.Petina, G.I.Popov

and N.B.Tarasova, Zashchita Mettalov, (5) May (1992) 845-848.

49. P.Agarwal and D.Landolt, Material Science Forum, 289-292 (2) (1998)

1229-1236.

50. Ghebramichael Ghabremedhin and Gurmeatsingh, Transactions of the

SAEST, 35 (2) April-June (2000) 38-44.

54

51. S.A.Seliman, S.M.Abd El-Motaal and M.Y.Mourad, J.Electro

Chem.Soc.India, 48 (4) (1999) 356-360.

52. S. Karthikeyan, G. Subramanian, K. N. Srinivasan and R.Venkatesh,

Eleventh National Convention of Electrochemists, Trichy, 26-27 Org. by

SAEST, CECRI and Bishop Heber College, Trichy, Dec.26-27 (2003) 26.

53. Milan Bartus, Katerina Bilkova and Norman Hackerman, Euro.Corr. 2003 –

The European Corrosion Congress, Hungary, Sep.28-Oct.2 (2003) 46.

54. B.Cook, Eur.Pat, Appl.Ep360, 747 (Cl.CO 7F9/38), 28 Mar (1990) GB

Appl.88/22, 144, 21 Sep (1988).

55. R. Ashcraft, G.Bohnsack, R.Holm, R.Kleinstueck and S.Stop, Mater.Perf.,

27 (1988)31.

56. J.G.Grierson, D.Spear and C.A Jones, Eur.Pat.Appl. EP 283,191(Cl.C23

F11/18) 21, Sep 1988, USAppl.27, 714, 19 Mar (1987).

57. R.J.Lipinski, K.Y.Chang, U.S. US4, 798,675(Cl.210-700; CO2F5/14). 17

Jan 1989, Appl.110, 138, 19Oct. (1987).

58. W.A.Mitchell, U.S.US4, 717,542 (Cl.422-15; C23 F11/16) 05. Jan 1988,

Appl.6, 393, 23 Jan (1987).

59. Kunitsugu Aramaki, Corrosion Science, 42 (11) Nov.(2000)2023-2036.

60. Kunitsugu Aramaki, Corrosion Science, 42 (11) Nov. (2000) 1975-1991.

61. H.Malik, Anti-Corrosion Methods and Materials, 47 (2) Apr.(2000)88-93

62. H.Malik, Anti-Corrosion Methods and Materials, 48 (6)Oct.(2001) 364-370

63. Kunitsugu Aramaki, Corrosion Science, 43 (10) Oct. (2001)1985-2000.

55

64. P.Sakthivel, G. Paruthimal Kalaignan, A.Gopalan and T. Vasudevan, Tenth

National Cong. on Corrosion Control, Madurai, Organised by NCCI,

Karaikudi, 6-8 Sep.(2000) 281-284.

65. A.Chetouani, B.Hammouti, T.Benhadda and M. Daoudi, Applied Surface

Science, 249 (1-4) 15 Aug.2005 (375-385)

66. Nathalie, Francis Moran, Nadine Pebere, and Bernard Tribollet, Corrosion

Science, 47 (3) Mar. (2005) 593-604.

67. S.Bilgic, Materials Chemistry and Physics, 76(1) 28th July (2002) 52-58.

68. Maria Forsyth, Craig M.Forsyth, Kerryn Wilson, Tom Behrsing and Glen

B.Deacon, Corrosion Science, 44 (11) Nov (2002) 2651-2656.

69. G.Blustein, J.Rodriguez, R.Romanogli and C.F.Zinola, Corrosion Science,

47 (2) Feb. (2005) 369-383.

70. G.Blustein, and C.F.Zinola, Journal of Colloid and Interface Science, 278

(2) 15th Oct (2004) 393-403.

71. S.E.Faidi and J.D.Scantlebury, Proc. of the Sixth Euro.Symp. on Corrosion

Inhibitors, Ferrara, Italy (8) (1985) 1187-1195.

72. S.Turgoose, Proc. of Sixth Euro. Symp.on Corrosion Inhibitors, Ferrara,

Italy, (8) (1985) 1041-1050.

73. D.M.Brashes and A.D. Mercer, Br.Corros.Journal, 3(1968)120.

74. A.D. Mercer, Br.Corros.Journal, 14 (3) (1979)179.

75. D.M.Brasher, D.Reichenberg and A.D.Mercer, Br.Corros.Journal,

3(1968)144.

56

76. H.C.Gatos, First European Symposium on Corr. Inhibitors, Ferrara, Italy,

(1960) 257.

77. P.Hersch, J.B.Hare, A.Robertson and S.M.Sutherland, Journal Appl.Chem.,

11 (1961) 246.

78. D.E.Davies and Q.J.M. Slaiman, Corrosion Science, 11(1971) 671.

79. C.L.Page and J.E.O.Mayne, Corrosion science,12(1972)679.

80. M.Fisher, Z.Phys. Chemie, Leipzig, 258 (1977) 897.

81. W.Forker, G.Reinhard and D.Rahner, Corrosion Science, 19(1979)745.

82. J.E.O.Mayne and C.L.Page, Br.Corros.Journal, 9 (1974)223.

83. I.N.Putilova , S.A.Balezin and V.P.Barannik, Metallic Corrosion Inhibitors,

Pergaman, Oxford (1960)60.

84. R.F.Weinland and A.Herz, Berichte, 45(1912)2662.

85. A.Earnshaw, B.N.Figgis and J.Lewis, J.Chem,Soc. (A) (1966) 1656.

86. G.J.Long, W.T.Robinson, W.P.Tappmeyer and D.L.Bridges, J.C.S. Dalton,

(1973) 573.

87. O.Lahodny-Sarc and P.Orlovic-Leko, Proc.of the Seventh European

Symposium on Corrosion Inhibitors, Ferrara, Italy, (9)(1990)1025-1032.

88. A.S. Fouda, A.Abd El-Aal and A.B.Kandil, Anti-Corrosion Methods and

Materials, 52(2) (2005)96-101.

89. C.V.Agrawal, C.Chakrabarty and M.M.Singh, Corrosion, 39(12) (1983)

461.

57

90. Chakarabarty, M.M.Singh, P.N.S. Yadav and C.V. Agrawal, Trans.

SAEST, 18 (1) (1983) 13-20.

91. M.N.Moussa, M.M.El-Tagoury, A.A.Radi, S.M.Hassan, Anti-Corrosion

Methods and Materials, 37 (3) March (1990) 4-8.

92. A.V.Fokin, M.V.Pospelov, Yu.N.Shekhter, Ye.S.Churshukov, L.P.Maiko

and A.Ya.Sergeykin Key Eng.Mat, 20-28 (1-4) (1987)1.

93. R.K.Dinnappa and S.M.Mayanna, Journal of Applied Electro Chemistry,

11(1) Jan (1981)111-116.

94. S.Bilgic and H.Yilmaz, Materials Chemistry and Physics, 79(1) 5 March

(2003)5-8.

95. Frederic Blin, Stuart G.Leary, Glen B.Deacon, Peter C.Junk and Maria

Forsyth, Corrosion Science, 48 (2) Feb. (2006) 404-419.

96. J.M.Abd-El.Kadher, A.A.El.Warraky and A.M.Abd El Aziz, Br.Corros.J. ,

33 (2) (1998) 152-157.

97. Z.Lu, S.Zheng, Y.Zhu, T.Chen, G.Zhou and D.Pan, Haudong Xueyuan

Xuebuo, 3, (1982), 403-409.

98. Z.Cai, Fuguang and Z.Lu: Fushi Yu Fanghu, 20(12) (1999) 537-538.

99. M.R.Nagaraju, H.B.Rudresh, R.K.Dinnappa and S.M.Mayanna, Proc.of the

Second National Conf.on Corr.and its Control, Calcutta, Org. by SAEST,

Dec.(1979) 363-376.

100. S.Bilgic and M.Sahin, Proceedings of Ninth European Symposium on

Corrosion Inhibitors, Ferrara, Italy, 2 (2000)771.

58

101. F.Blin, S.G.Leary, K.Wilson, G.B.Deacon, P.C.Junk and M.Forsyth,

Euro.Corr.2003-The European Corrosion Congress, Hungary, Sep 28-

Oct.2,(2003) 25.

102. R.D.Granata, P.C.Santiesteban and H.Leidheiser Jr, Sixth Symposium on

Corrosion Inhibitors, Ferrara, Italy, (8) (1985) 411-425.

103. S.Stefanova, Proc.of Sixth Symposium on Corrosion Inhibitors, Ferrara,

Italy, (8) (1985) 1277-1282.

104. Skolastika, Kuczkowska, Korroz, Figy. 28(1988)124.

105. P.Kern and D.Landolt, Corrosion Science, 44 (8) Aug.(2002) 1809-1824.

106. M.G. Pavlovi, Lj. J. Pavlovi, I.D.Doroslova ki and N.D. Nikoli,

Hydrometallurgy, 73(1-2) April (2004) 155-162.

107. D.Eurof Davies and Q.J.M. Slaiman, Corrosion Science, 13 (11) (1973)

891-905.

108. T.Szauer and A.Brandt, Corrosion Science, 23 (12) (1983) 1247-1257.

109. O.P.Lykov, T.P.Vishnyakova, T.M.Luchkina, Chemistry and Technology

of Fuels and Oils, 18(1-2) Jan-Feb (1982)7-10.

110. E.Rocca and J. Steinmetz, Corrosion Science, 43 (5) May (2001) 891-902.

111. T.Szauer, Corrosion Science, 23 (5) (1983) 481-494.

112. T.Szauer and A.Brandt, Corrosion Science, 23 (5) (1983) 473-480

113. O.Lahodny-Sarc and S.Popov, Surface and Coatings Technology, 34 (4)

June-July (1988) 537-547.

114. T.Szauer and A.Brandt, Electrochimica Acta, 26 (9) Sep.(1981) 1257-1260.

59

115. Reinaldo Simoes Goncalves, Natalie Maria Coradini and Winston Xaubet

Olivera, Corrosion Science, 33 (11) Nov.(1992) 1667-1675.

116. V.B.Singh and R.N.Singh, Corrosion Science, 37 (9) Sep. (1995)1399-

1410.

117. G.Gunasekaran, R.Natarajan and N.Palaniswamy, Corrosion Science, 43 (9)

Sep (2001) 1615-1626.

118. N.Muthumani, A. John Amalraj, Susai Rajendran and R.Ramaraj, Eleventh

National Convention of Electrochemists, Trichy, Organized by SAEST,

CECRI and Bishop Heber College, Trichy, 26- 27th,Dec(2003)27.

119. C.A.Baah and J.I.Baah, Anti-Corrosion Methods and Materials, 47, (2)

April (2000) 105-108.

120. H.B.Shao, J.M.Wang, Z.Zhang, J.Q.Zhang and C.N.Cao, Materials

Chemistry and Physics, 77 (2) 15 Jan.(2003) 305-309.

121. C.M.V.B. Almeida and B.F.Giannetti, Materials Chemistry and Physics, 69

(1-3) 1Mar. (2001) 261-266.

122. B. Müller, W. Kläger and G. Kubitzki, Corrosion Science, 39 (8) Aug.

(1997) 1481-1485.

123. M.M Singh and Archana Gupta, Indian Journal Chem.Technology, 3 (1996)

32.

124. M.M Singh and Archana Gupta, Fifth National Conference Purvanchal

Academy of Science, Varanasi, Dec.23-25 (1993)26.

125. C.Giacomelli, F.C. Giacomelli, J.A.A Baptista, A.Spinelli, Anti-Corrosion

Methods and Materials , 51(2) March (2004)105-111.

60

126. Mercer and C.William, ASTM Special Technical Publication, (1192)

(1993) 44-62.

127. F.C.Giacomelli, C Giacomelli, M.F.Amadori, V.Schmidt and A.Spinelli,

Materials Chemistry and Physics, 83 (1) 15 Jan (2004) 124-128.

128. K.K.Sagoe-Crentsil, V.T.Yilmaz and F.P.Glasser, Cement and Concrete

Research, 23 (6) Nov.(1993)1380-1388.

129. P.Spathis, E.Papastergiadis, G.Stalidis, G.Papanastasiou,

http://www.jcse.org/vol.2.extended abstract 29.

130. B.Muller, Corrion Science, 46 (1) Jan (2004)159-167.

131. S.A. Abd El-Maksoud, S.M.Rashwan, M.A. Ibrahim and S.M.Abd El-

Wahaab, Electrochimica Acta, 50 (10) 15 March (2005) 1985-1991.

132. R.C.Pemberton, A.D.Mercer, E.J.Wright and J.G.N.Thomas, Proc.of Sixth

Symposium on Corrosion Inhibitor , Ferrara, Italy, 2 (8) (1985) 1241-1249.

133. G.Butler and A.D.Mercer, Br.Corros. J. 12(3) (1977) 171.

134. E.W.Beale, B.Bedford and M.J.Sims, Symposium: Engine Coolant

Testings, State of the Art, held in Atlanta, GA, USA, April 1979 ASTM

special technical publication 705 edited by W.H.Ailor Phildelphia,

American Society for Testing and Materials, (1980) 295.

135. A.John Amalraj, M.Sundaravadivelu, A.Peter Pascal Regis and

S.Rajendran, Tenth National Cong. on Corrosion Control, Madurai,

Organised by NCCI, Karaikudi, 6-8 Sep. (2000) 220-226.

136. A.John Amalraj, Susai Rajendran, A.Peter Pascal Regis and

M.Sundaravadivelu, Euro Corr.2003-The European Corrosion Cong.,

Hungary, Sep28- Oct 2 (2003) 26.

61

137. C.Thangavelu, M.Sundaravadivelu and S. Rajendran, Proc. of Tenth

National Cong.on Corrosion Control, Madurai, Sep. (2000) 234-240.

138. Dong-Jin Choi, Seung-Jae You and Jung-Gu Kim, Materials Science and

Engneering A, 335 (1-2) 25 Sep. (2002)228-235.

139. G.Ruba Helen Florence, A. Noreen Anthony, J. Wilson Sahayaraj, A. John

Amalraj and Susai Rajendran, Indian J. of Chemical Technology, 12, July

(2005) 472-476.

140. Felicia Rajammal Selvarani, S. Santhamadharasi, J. Wilson Sahayaraj, A.

John Amalraj, Susai Rajendran, Bulletin of Electrochemistry’, 20 (12)

Dec.(2004)561-565.

141. A.Arichandran, Wilson Sahayaraj and Susai Rajendran, Eleventh National

convention of Electrchemists, Trichy, Organised by SAEST, CECRI and

Bishop Heber College, Trichy, 26-27 Dec.(2003)35.

142. G.T.Vigant, A.B.Englin, N.N.Zakharova, Protection of Metals, 24 (3) Jan

(1989) 416-417.

143. P.Falewicz and S.Kuczkowska,Werkst. Korros. , 43(1992) 215.

144. J.Kubicki, S.Kuczkowska, P.Falewicz and B.Pyrwanow, Proc. Sixth

Europ.Symp.on Corrosion inhibitors, Ferrara, Italy, 2(1985)1131-1144.

145. E.Medico, E.Otero and J.A Gongalez, Rev.Metal, 28 (1992) 22.

146. W.Chiesa, R.Cigna, I.S.Di Simone, G.Gusmano and G.F.Mazzani,

Proc.Sixth Europ.Symp. on Corr.Inhibitors, Ferrara, Italy, (8) (1985)1295-

1305.

147. Chen Jiajian and Wang Xiaoming, Proc.Seventh Europ.Symp.on Corrosion

inhibitors, Ferrara, Italy (9) (1990)1049-1054.

62

148. S.Rajendran, B.V.Apparao and N.Palaniswamy, Journal Electrochem.Soc.,

India, 47(1) (1998) 43-48.

149. Susai Rajendran, R. Maria Joany, B.V.Apparao and N. Palaniswamy,

Indian Journal of Chemical Technology, 9, May (2002) 197-200.

150. S.Rajendran, B.V.Apparao and N.Palaniswamy, Anti-Corrosion Methods

and Materials, 45 (6) (1998)397-401.

151. S.Rajendran, B.V.Apparao and N.Palaniswamy, Anti-Corrosion Methods

and Materials, 45, (3) (1998)158-161.

152. Hwa, Chih M., Mitchell, Wayne A.U.S. US 4, 649, 025, (Cl.422-15; C23

F11/16)10 Mar (1987), Appl.776311, 16 Sep. (1985).

153. Wang, Zumo and Cai, Lankun, Huadong Huagong Xueyuan Xuebao, 15

(1989)605.

154. Ito, Kenjchi, Kanbe, Osamu, Yoshida, Koji, Japan Kokai Tokkyo Koho, JP

62 96, 683 (87 96 ,683 ) Cl.C23 F11/167). 06 May (1987), Appl.85/234,

441, 22 Oct (1985).

155. Yang Zhang, Li Shouchun and Tang Li, Proc. Sixth Europ.Symp.on

Corrosion Inhibitors, Ferrara, Italy, (8) (1985) 999-1001.

156. S.Venugopalan, B.V.Apparao, G.Venkatachari, S.Muralidharan and

S.V.Narasimhan, Eleventh National Convention of Electrochemists (NCE-

11), Trichy, Organised by SAEST, CECRI and Bishop Heber College,

Trichy, 26-27 Dec.(2003) 29.

157. B.V.Apparao and S Srinivas Rao, Eleventh National Convention of

Electrochemists (NCE-11), Trichy, Organised by SAEST, CECRI and

Bishop Heber College, Trichy, 26-27 Dec.(2003) 29.

63

158. C.Wrubl, E.D.Mor and U.Montini, Proc.Sixth Europ.Symp.on Corrosion

Inhibitors, Ferrara, Italy, (8) (1985) 557-577.

159. Susai Rajendran, B.V. Apparao and N. Palaniswamy, Electrochimica Acta,

44(1998) 533-537.

160. B.V. Meena, Noreen Anthony, K. Mangayarkarasi P. Jayaram and

S.Rajendran, Journal Electrochem.Soc., India, 50 (3) (2001)138-142.

161. B.V.Meena, Noreen Anthony, K.Mangayarkarasi, P.Jayaram and

S.Rajendran, Kinetics of Corrosion of Carbon Steel in the Presence of

CMC, Proc. of Tenth National Congress on Corr. Control, Madurai,

Organised by NCC of India, CECRI, 6-8 Sep (2000) 241-247.

162. P.Manjula, S.Manonmani, P.Jayaram and S.Rajendran, Anti-Corrosion

Methods and Materials, 48 (5) Sep. (2001) 319-324.

163. A.Cepero, Rev.Cienc, Quim.16 (No.Espec (1985) 49.

164. A.Cepero, Rev.Cienc, Quim.16 (No.Espec (1985) 55.

165. F. Soeder, Kenneth and S.Roti, Joseph, Proc. – 48th Inter Water. Conf. ,

Eng.Soc. West.Pa.(1987)115.

166. Y.J.Qian and S. Turgoose, Br.Corrosion J., 22(1987) 268.

167. Yu.I.Kuznetsov, E.A.Trunov, and I.V.Starobinskaya, Zashch. Met., 24

(1988) 389

168. Yu.I.Kuznetsov. T.A.Agalarova and A.M.Kyazimov, Azerb, Khim. Zh., (4)

(1986)119.

169. I.Sekine and Y.Hirakwa, Corrosion, 42(1986) 276.

64

170. Y. Gonzales, M.C. Lafont, N. Pebere and F.Moran, Proc. of the Eighth

Europ. Symposium on Corrosion Inhibitors, Ferrara, Italy, 10 (1995) 453-

463.

171. S.Ramesh, S.Rajeswari and S. Maruthamuthu, Materials Letters, 57 (29)

Nov.(2003) 4547-54.

172. S.Ramesh and S.Rajeswari, Corrosion Science, 47 (1) Jan. (2005)151-169.

173. S.Rajendran, B.V.Apparao and N.Palaniswamy, Journal of

Electrochem.Soc. India, 48 (1) (1999) 89-93.

174. S. Rajendran, B.V. Apparao and N.Palaniswamy, Anti-Corrosion Methods

and Materials, 44 (5) (1997) 308-313.

175. S. Rajendran, B.V. Apparao and N.Palaniswamy, Bulletin of Electro

Chemistry, 13(12) Dec. (1997) 441-447.

176. S.Rajendran, R.M.Joany and N.Palaniswamy. Tenth National Cong. on

Corrosion Control, Madurai, Organised by NCCI, Karaikudi, 6-8

Sep.(2000) 251-261

177. D.Bernard, T.E. Pou, and M.Haim, Proc. of Sixth Europ. Sympo. On

Corrosion Inhibitors, Ferrara, Italy, 8 (1985) 1465-1471

178. M.Manimegalai, P.Rajeswari, S. Mohanan, S.Maruthamuthu and N.

Palaniswamy, Proc. of Tenth National Cong.on Corr.Control, Madurai,

Org.by NCCI, Karaikudi Sep.(2000) 153-158.

179. D.G.Davies, M.R. Parsek, J.P. Pearson, Science, 280 (1998) 259.

180. www.ibt.dtu.dk/im/mme/pdf/Hentzer-2002-1

65

181. B.A.Iwalokun ,Y.A. Olukosi , A..Adejoro , J.A.Olaye, O.Fashade African

Journal of Biotechnology, ACADEMIC JOURNALS, 3 (1684-5315) (2004) 99-

104

182. Richard E. Glover, Royston R. Smith, Martin V. Jones, Simon K. Jackson,

Christopher C. Rowlands, FEMS Microbiology Letters, 177(1) August

(1999)57

183. G.H.Y. Lin, K.A. Voss and T.J.Davidson, Food and chemical Toxicology,

29 (12) (1991) 851-854.

184. www.patentstorm.us/class/424/413- Cellulosic _material_or_ building_

material.html.

185. infochems.com/chemdb/product_list.

186. Abdul Fattah, K.M.Atia, F.S.Ahmed and M.I. Roushdy, Corr. Prev. and

Control, 33(1986)67.

187. F.B.Growcock and W.W.Frenier, J.Electrochem. Soc., 135(1988)817.

188. F.B. Growcock, V.P.Lopp and R.J.Josinski, J.Electrochem.Soc. ,

135(1988)823.

189. G.N.Mu, T.P.Zhao, M.Liu and T.Gu, Corrosion, 52(1996)853.

190. S.Rajendran, B.V.Apparao and N.Palaniswamy, Br.Corrosion

J.,33(1998)315-317

191. G.Bereket and A.Yurt, Anti-Corrosion methods and Materials, 49 (3) May

(2002) 210-220.

192. Lin Niu, Hu Zhang, Fenghua Wei, Suxiang Wu, Xiaoli Cao and Pengpeng

Liu, Applied Surface Science, 252(5) 15 Dec.(2005) 1634-1642.

193. M.T.Saeed and S.A.Ali, Anti-Corrosion methods and Materials, 50 (6)

(2003) 436-441.

66

194. D.Bernard, M.Haim and T.E.Pou, Proc.of the Sixth Euro.Symp.on

Corrosion Inhibitors, Ferrara, Italy (8) (1985) 1497-1504

195. T.P.Hoar and R.D.Holliday, J.App.Chem, 3 (1953)502

196. S.Rajendran, B.V.Apparao and N.Palaniswamy, Anti-Corrosion methods

and Materials, 47(2000) 11.

197. P.Manjula, S.Manonmani, P.Jayaram, S.Rajendran, Tenth National

Congress on Corr. Control, Madurai, Org.by NCC of India, Karaikudi and

CECRI, 6-8 Sep (2000) 227-233

198. Houyi Ma, Shenhao Chen, Bingsheng Yin, Shiyong Zhao and Xiangqian

Liu, Corrosion Science, 45 (5) May (2003) 867-882.

199. R.Karpagavalli and S.Rajeswari, Anti-Corrosion methods and Materials,

45(1988) 333.

200. T.Y.Soror and M.A.El-Ziady, Materials chemistry and Physics, 77(3) 30

Jan.(2003) 697-703.

201. A.Lalitha, S.Ramesh and S. Rajeswari, Electrochimica Acta, 51 (1) 5 Oct.

(2005) 47-55.

202. Michael.L.Free, Corrosion Science, 44 (12) Dec. (2002) 2865-2870.

203. Lin Wang, Guo-Jian Yin and Jian-Guo Yin, Corrosion Science, 43(6) June

(2001)1197-1202.

204. S.A.Abd El-Maksoud, Journal of Electroanalytical Chemistry, 565 (2) 15

April (2004)321-328.

205. G.Suguna, Noreen Anthony and Susai Rajendran, Eleventh National

Convention of Electrochemists, (NCC-11), Trichy, Org by SAEST, CECRI

and Bishop Heber College, Trichy, 26-27 Dec.(2003) 35.

67

206. Rong Guo, Tianqing Liu and Xun Wei, A Physicochemical and

Engineering Aspects, 209 (1) 4 Sep.(2002)37-45.

207. Sayed.S.Abd El Rehim, Hamdi, H.Hassan and Mohammed.A.Amin,

Materials Chemistry and Physics, 78 (2) 17 Feb (2003)337-348.

208. R.F.V.Villamil, G.G.O.Cordeiro, J.Matos, E.D.Elia and S.M.L.Agostinho,

Materials Chemistry and Physics, 78 (2), 17 Feb (2003) 448-52.

209. Ruth F.V.Villamil, Paola Corio, Silvia, M.L.Agostinho and Joel C.Rubin,

Journal of Electroanalytical Chemistry, 472 (2) 30 Aug. (1999) 112-119.

210. Susai Rajendran, S.Mary Reen Kala, Noreen Anthony and R.Ramaraj,

Corrosion Science, 44 (10) Oct. (2002) 2243-2252.

211. C.Monticelli, G.Brunoro, A.Frignani, F.Zucchi, Corrosion Science, 32 (7)

(1991) 693-705.

212. Mirghasem Hosseini, Stijn F.L.Mertens and Mohammed R. Arshadi,

Corrosion Science, 45 (7) July (2003)1473-1489.

213. Susai Rajendran, A.John Amalraj, J.Wilson Sahayaraj, R.Joseph Rathish,

Noreen Anthony, and N. Palaniswamy , Transactions of the SAEST, 40

(2005) 35-39.

214. S.Rajendran, S.P.Sridevi, N.Anthony, Amalraj and M. Sundaravadivelu,

Anti-Corrosion Methods and Materials, 52 (2) Feb. (2005) 102-107.