Application of Carboxymethyl Chitosan-Benzaldehyde as...

Research ArticleApplication of Carboxymethyl Chitosan-Benzaldehyde asAnticorrosion Agent on Steel

Handoko Darmokoesoemo 1 Suyanto Suyanto1 Leo Satya Anggara1

Andrew Nosakhare Amenaghawon2 and Heri Septya Kusuma 3

1Department of Chemistry Faculty of Science and Technology Airlangga University Surabaya 60115 Indonesia2Department of Chemical Engineering Faculty of Engineering University of Benin PMB 1154 Ugbowo Benin City Edo State Nigeria3Department of Chemical Engineering Faculty of Industrial Technology Institut Teknologi Sepuluh NopemberSurabaya 60111 Indonesia

Correspondence should be addressed to Handoko Darmokoesoemo handokodarmokoesoemogmailcomand Heri Septya Kusuma heriseptyakusumagmailcom

Received 26 August 2017 Revised 9 December 2017 Accepted 20 December 2017 Published 16 April 2018

Academic Editor Sebastien Deon

Copyright copy 2018 Handoko Darmokoesoemo et al This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Corrosion is one of the problems that is often found in daily life especially in petroleum and gas industry Carboxymethyl chitosan-(CMC-) benzaldehydewas synthesized as corrosion inhibitor for steel Corrosion ratewas determined by potentiostatic polarizationmethod in HCl 1M Dripping and coating two different treatment were used to drop and coat steel by CMC-benzaldehyde Theresults showed that CMC-benzaldehyde could inhibit the corrosion rate of steel with concentration of 1 g 3 g 5 g and 7 g in 60mLof solvent Coating steel with CMC-benzaldehyde with concentration of 7 g60mL of solvent and starch of 01 gmL showed thehighest efficiency to inhibit corrosion rate of steel These treatments give corrosion efficiency of 998

1 Introduction

Corrosion is one of the most common problems found ineveryday life especially in the oil and gas processing industryCorrosion cannot be prevented or stopped but its rate ofdestruction can be controlled Corrosion is the degradation(destruction or degradation of quality) of metal propertiesthrough electrochemical reactions that are natural and takeplace by themselves due to chemical phenomena with theenvironment The factors that cause corrosion include airpollution levels temperature humidity and the presence ofchemicals that are corrosive [1]

Corrosion-induced impacts can be direct and indirectimpacts Direct impacts include damage to equipmentmachinery and building structures Indirect impacts resultfromcessation of production activities due to the replacementof equipment damaged by corrosion Indirect costs incurredare generally larger than direct costs [2] Therefore variousattempts are made to inhibit corrosion

In the oil drilling and processing industry corrosionbecomes an inseparable problem Uncontrolled corrosionrate can result in a malfunction of the equipment usedespecially on offshore oil drilling platforms with high salineenvironments

Corrosion that occurs in the metal causes a loss that isnot small financially The economic factor becomes a veryimportant motivation for many current studies to be able toovercome and inhibit the rate of corrosion According to arecent study the losses suffered by industry and governmentin the United States amount to approximately 276 billion USdollar or about 31 percent of GrossDomestic Product (GDP)Studies on corrosion in Australia England Japan and othercountries have also been conducted Nearly every countryspends about 3-4 percent of Gross Domestic Product (GDP)to overcome corrosion Total losses due to corrosion can beavoided around 25ndash30 percent if corrosion prevention can bedone effectively [3]

HindawiInternational Journal of Chemical EngineeringVolume 2018 Article ID 4397867 9 pageshttpsdoiorg10115520184397867

2 International Journal of Chemical Engineering

There are various efforts of metal protection to overcomecorrosion among others surface coating and cathode pro-tection systems require a high cost because of the selectionof inhibitors used The effort has also not been effective inovercoming corrosion In this research corrosion inhibitorfrom organic material as anticorrosion is usedThis inhibitoris chosen because it has a high affinity on the metal withhigh efficiency and being friendly to the environment Thecorrosion inhibitor used is namely carboxymethyl chitosan(CMC) which is substituted with benzaldehyde

Carboxymethyl chitosan (CMC) is a derivative of chi-tosan derived from chitin isolated from terrestrial inverte-brates marine invertebrates and fungi which are numerousin nature In invertebrates chitin serves as an exoskeletoncomposite matrix whereas in fungi it functions as a cell wallshaper Chitosan is a soluble solid in acetic acid and easilydegraded but the application of chitosan is limited because itis not water soluble [4]

The use of CMC in this study is preferred over chitosanitself This is because CMC has an important characteristicthat is water soluble high gel forming capacity low toxicityand good biocompatibility so that the application will bewider [5] In addition CMC is widely used because it isamphiprotic which contains the -COOH and -NH2 groupsin its molecules that have many free electron pairs

In this study the -NH2 group present in CMC (actingas base) is substituted with benzaldehyde to form car-boxymethyl chitosan-benzaldehyde (CMC-benzaldehyde)compound These compounds are expected to be used as aneffective and effective anticorrosion in inhibiting the corro-sion rate on steel CMC-benzaldehyde is used as a corrosioninhibitor due to the presence of heteroatoms (O and N) thephi bond formed between CMC and benzaldehyde and thenumber of free electrons that can support the inhibitor inchemisorption with the metal by coordination [6]

Therefore in this study the inhibition of corrosion ratewas carried out on the steel in the medium of HCl 1Musing the CMC-benzaldehyde inhibitor The method usedto determine the corrosion rate is the measurement of theintensity of corrosion current on steel with potentiostaticpolarization

2 Materials and Methods

21 Materials and Tools The materials used in this studywere chitosan from Good Manufacturing Practice glacialacetic acid NaOH chloroacetic acid isopropanol ethanol998 distilled water double-distilled water benzaldehydecommercial steel filter paper cassava andHCl 37while thetool used in this research is Fourier Transform Infrared Spec-trometer (FTIR) SHIMADZU Potentiostat PGSTAT302Ncorrosion test instrument coupled with computer and Auto-lab NOVA software and SEM-EDX Carl Zeiss EVOMA 10

22 Synthesis of CMC and CMC-Benzaldehyde

221 Synthesis of CMC A total of 10 g of chitosan wasdissolved in 400mL of acetic acid 2 The soluble chitosanwas added to 135 g of NaOH and was reacted over the water

bath at 50∘C for 1 hour The solution was refluxed and addedto 15 g of chloroacetic acid which has been dissolved in 20mLof isopropanol The mixture was reacted for 4 hours at 50∘CThe treated mixture was filtered off with a Buchner funneland washed with ethanol 70 The obtained precipitate isdried at room temperatureThe result is a CMCwhich is thencharacterized using FTIR [8]

222 Synthesis of CMC-Benzaldehyde A total of 20 g ofCMCwas dissolved in 400mL of distilled waterThe solutionwas reacted with benzaldehyde-ethanol with a ratio of 1 1(5mL of benzaldehyde mixed with 5mL of ethanol) Thetemperature used during the reaction takes approximately50ndash60∘C The reaction was carried out for 5 hours and thenfiltrate and the precipitate was filtered using a Buchner funneland washed with ethanol 70 The precipitate obtained isthe result of the synthesis of CMC-benzaldehyde CMC-benzaldehyde obtained was characterized using FTIR [9]

23 Preparation of Starch A total of 1 kg of cassava is cleanedand peeled Then the cassava is smoothed using a grinderFinely ground cassava is then soaked in distilled water for24 hours The filtrate and the precipitate are separated bydecantation The precipitate obtained is dried to obtain astarch made from cassava A total of 5 g of starch wasdissolved in 50mL of hot aquades by stirring until a homoge-neous solution was obtained This formed starch solution ismixed in CMC-benzaldehyde

24 Treatment for Steel The steel used in this study wascleaned by sand and cut with length of 20mm width of10mm and thick of 1mmThe chemical composition contentof the steel was tested using EDX (Energy Dispersive X-Ray)analysis

25 Testing of Corrosion Rate on Steel in HCl 1M

251 Testing of Corrosion Rate on Steel without Addition ofCMC-Benzaldehyde The steel is first immersed in 100mLof HCl 1M for 120 hours After the corrosion process runsduring that time the steel is taken and washed with double-distilled water Furthermore the steel is left for a while andthen heated in an oven at a temperature of 45ndash50∘C for10 minutes Testing of corrosion rates on steels in HCl 1Mwithout addition of CMC-benzaldehyde was performed bypotentiostatic polarization method as shown in Figure 1

252 Testing of Corrosion Rate on Steel with the Additionof CMC-Benzaldehyde Tests of corrosion rates on steels inHCl 1M were carried out with two treatments drippingand coating wherein each treatment was added to CMC-benzaldehyde without starch and with starch Drippingwith the addition of CMC-benzaldehyde was performed bydissolving CMC-benzaldehyde of 1 g 3 g 5 g and 7 g in amixture of 20mL of distilled water 20mL of acetic acid2 and 20mL of alcohol at a ratio of 1 1 1 Subsequentlya 100mL of HCl 1M was added to the solution of CMC-benzaldehyde by stirring until homogeneous The solution is

International Journal of Chemical Engineering 3

IE

E Potentiostat

RE

CEWE

Figure 1 The series of equipment for potentiostatic polarizationmethod (working electrode is carbon steel reference electrode isHg2Cl2 and counter electrode is platinum)

closed and left for 72 hours Next the steel is immersed in thesolution for 120 hours

Dripping with the addition of CMC-benzaldehyde usingstarch was performed by dissolving CMC-benzaldehyde of1 g 3 g 5 g and 7 g in a mixture of 20mL of distilled water20mL of acetic acid 2 and 20mL of alcohol at a ratioof 1 1 1 Furthermore the solution of CMC-benzaldehydewas added to starch solution of 1mL 3mL 5mL and 7mLwith a concentration of 01 gmL and 100mL of HCl 1MThe solution is closed and left for 72 hours Next the steelis immersed in the solution for 120 hours

Coating with the addition of CMC-benzaldehyde wasperformed by dissolving CMC-benzaldehyde of 1 g 3 g 5 gand 7 g into a mixture of 20mL of aquades 20mL of aceticacid 2 and 20mL of alcohol at a ratio of 1 1 1 The steel isthen immersed in the solution for 72 hours After a prede-termined time the steel is taken and put into the oven so thatCMC-benzaldehyde can adhere to the steel Furthermore thesteel is immersed in 100mL of HCl 1M for 120 hours

Coating with the addition of CMC-benzaldehyde usingstarch was carried out by dissolving CMC-benzaldehyde of1 g 3 g 5 g and 7 g in 20mL of aquades 20mL of acetic acid2 and 20mL of alcohol at a ratio of 1 1 1 Each solutionwasadded to starch solution of 1mL 3mL 5mL and 7mL witha concentration of 01 gmL Furthermore steel is immersedin the solution for 72 hours After a predetermined time thesteel is taken and put into oven so that CMC-benzaldehydeand starch can adhere to the steel Furthermore the steel isimmersed in 100mL of HCl 1M for 120 hours

Tafel line Tafel line

Corrosioncurrent

CZ CZPotential (V)

c

Log

of in

tens

ity (m

A)

Figure 2 The curve between potential against log of currentintensity

After the corrosion process takes place with the drippingand coating treatment during that time the steel is removedand washed with double-distilled water Furthermore thesteel is left for a while and then heated in an oven ata temperature of 45ndash50∘C for 10 minutes The corrosionrate test on steel in HCl 1M with the addition of CMC-benzaldehyde was performed by potentiostatic polarizationmethod as shown in Figure 1

26 Determination of Corrosion Rate In this study thedetermination of corrosion rate was done by determining theintensity of corrosion current with potentiostatic polarizationusing the correlation between potential with log of currentintensity to obtain intensity of corrosion current (119868corr) andcorrosion rate (Vcorr) as shown in Figure 2 The relationshipbetween the intensity of corrosion current (119868corr) and corro-sion rate (Vcorr) is illustrated by the following equation

Vcorr =013 times 119868corr times EW120588

(1)

where Vcorr is the rate of corrosion (mpy) 119868corr is the intensityof corrosion current (120583Acm2) EW is the equivalent weight(atomic weightvalence) (g) and 120588 is the density (gcm2)

The smaller corrosion rate of a material indicates thegreater resistance of the inhibitor in inhibiting corrosionConversely the greater corrosion rate of a material indicatesthe smaller resistance of the inhibitor in inhibiting corrosionThe intensity value of corrosion current (119868corr) is obtained byperforming Tafel analysis with semimanual way by extrapo-lating the linear part of a plot log of the current intensity withpotential at the current meeting of the anode and cathode

The determination of potential calculation zone (CZ) ofthe anode and cathode curves affects the slope of cathodecurve (120573119888) and the slope of anode curve (120573120572) which directly


HCl

Chitosan Sodium salt of CMC CMC

（Ｆ（2（

）ＭＩＪＬＩＪＨＩＦ 50∘C

O

H

H

OH

OHH

H

O

H

（2

（2

O

H

H

OH

OHH

H

O

H

（2

（2

（2

O

H

H

OH

OHH

H

O

H

（2

Figure 3 Synthesis of CMC from chitosan

determines the intensity value of corrosion current (119868corr)This is shown by the Stern-Geary equation as follows

119868corr =120573119888 times 120573120572

23 times (120573119888 + 120573120572) times 119860 times 119877119901 (2)

where 119868corr is the intensity of the corrosion current (120583Acm2)

120573119888 is the slope of cathode curve120573120572 is the slope of anode curve119860 is the area (cm2) and 119877119901 is the polarization resistance(kΩcm2) The slope value of the cathode and anode curvesfor each element or type of metal is not necessarily samedepending on the corresponding valence in the corrosionreaction that occurs

27 Testing Morphology on Steel The morphological test onsteel aims to find out the steel surface structure as a resultof the addition of inhibitors to corrosive media [10] Formorphological testing of steel samples the steel samples areplaced on top of the preparations and then observed byScanning Electron Microscope (SEM) so that the surfacestructure and corrosion type on the steel can be seen clearlyas a result of the addition of CMC-benzaldehyde

28 Data Analysis Data obtained from test results inthe form of current and potential using potentiostatPGSTAT302N were processed by Tafel analysis withsemimanual way to obtain the intensity of corrosion current(119868corr) and corrosion rate (Vcorr) The Tafel analysis isperformed by extrapolating the linear part of a plot log of thecurrent intensity with the potential at the current meeting ofthe anode and cathode From the intersection of the line theintensity of corrosion current (119868corr) is obtained that can beconverted to obtain the rate of corrosion (Vcorr) in accordancewith (1) In this research potentiostat PGSTAT302N withAutolab NOVA software is used so that the corrosionrate (Vcorr) can be obtained together with the intensity ofcorrosion current (119868corr) at the time of Tafel analysis from therelationship between the curve of the potential and the logof current intensity Data analysis of the effect of variationconcentration of CMC-benzaldehyde on the inhibition ofcorrosion rate on steel is shown in the formof graph and table

29 Inhibition Efficiency of CMC-Benzaldehyde against Cor-rosion Rate Inhibitor efficiency is an inhibitorrsquos ability toinhibit corrosion rate efficiently when compared to without

using inhibitors To determine the efficiency of inhibitor inreducing and controlling corrosion rate on carbon steel inthis study the efficiency of inhibitor is calculated using thefollowing equation

Inhibition efficiency () =1198811198960 minus 11988111989611198811198960times 100 (3)

where 1198811198960 is the corrosion rate without using inhibitor and1198811198961 is the corrosion rate using inhibitor

3 Results and Discussion

31 Synthesis of CMC-Benzaldehyde The synthesis of CMC-benzaldehyde is done by reacting CMC with benzaldehydeIn the formation of CMC-benzaldehyde CMC need to besynthesized by reacting chitosanwithNaOHand chloroaceticacid as shown in Figure 3 [7] CMC formed can dissolvecompletely in water

The formation of CMC-benzaldehyde occurs through thereaction mechanism of the formation of an imine The stageof imine formation which essentially occurs in two stagesis addition and elimination The first stage is the additionof the nucleophilic amine to carbonyl carbon which has apartial positive charge followed by the release of protonsfrom nitrogen and the acquisition of protons in oxygen Thesecond stage is the protonation of the OH group which canbe released as water in an elimination reaction The reactionmechanism of CMC-benzaldehyde formation is shown inFigure 4

32 Characterization of Chitosan CMC and CMC-Benzalde-hyde Using Fourier Transform Infrared Spectrometer (FTIR)Characterization using Fourier Transform Infrared Spec-trometer (FTIR) is used to determine the functional group ofa compound formed on a particular wave number The FTIRspectrum of chitosan and CMC according to Zheng et al [7]is shown in Table 1

The FTIR spectrum of chitosan used for the synthesis ofCMC can be seen in Figure 5The FTIR spectrum of chitosanshows the followingwave numbers 103377ndash108392 cmminus1 (C-O stretch) 115335 cmminus1 (bridge-O stretch) 142144 cmminus1 (N-H bending) 288338 cmminus1 (C-H stretch) and 344077 cmminus1(O-H stretch)

The FTIR spectrum of CMC can be seen in Figure 6The FTIR spectrum of CMC from the synthesis results


O

HH

OH

OHH

H

O

H

H

CMC Benzaldehyde

+O

NHHH

OH

OHH

H

O

H

CHH

O

HH

OH

OHH

H

O

H

CHHO

O

HH

OH

OHH

H

O

H

CHO

H

H

O

NHH

OH

OHH

H

O

H

CH

H

O

NHH

OH

OHH

H

O

H

CH

CMC-benzaldehyde

（2H（2H（2H

（2H （2H （2H

minus（2O

oplus

Hoplus

minusHoplus

oplus

oplus

⊖

（∙∙

2（∙∙

（∙∙

O∙∙

∙ ∙

O∙∙

∙ ∙

Figure 4 Reaction mechanism of CMC-benzaldehyde formation

Table 1 Analysis of functional groups of chitosan and CMC using FTIR

Functional groups Wave numbers according toZheng et al [7] (cmminus1)

Wave numbers of chitosan(cmminus1)

Wave numbers of CMCfrom the synthesis results

(cmminus1)C-O stretch 1030ndash1094 103377ndash108392 103377ndash108199Bridge-O stretch 1153 115335 115142N-H bending 1556 142144 159888C-H stretch 2881 288338 288917O-H stretch 3421 344077 343498COOminus 1407ndash1598 - 140794

shows the followingwave numbers 103377ndash108199 cmminus1 (C-O stretch) 115142 cmminus1 (bridge-O stretch) 159888 cmminus1 (N-H bending) 288917 cmminus1 (C-H stretch) 343498 cmminus1 (O-Hstretch) and 140794 cmminus1 (COOminus) while the wave numberof 140794 cmminus1 shows the existence of a new group formedfrom the esterification reaction of chitosan into CMC that isCOOminus

The functional groups formed on chitosan and CMC canbe seen in Table 1 The FTIR spectrum of CMC from thesynthesis results obtained in this study showed similar resultswith the FTIR spectrumofCMCaccording to Zheng et al [7]

The formation of CMC-benzaldehyde is demonstratedby the presence of new functional group the imines (C=N)and C=C aromatic which can be seen at the wave num-bers for those groups in the FT-IR spectrum shown inFigure 6 According to Pretsch et al [11] the wave number

for imine (C=N) is 1645 cmminus1 and for C=C aromatic is1600 cmminus1 The wave number of CMC-benzaldehyde fromthe synthesis results is 164131 cmminus1 for imines (C=N) and1450ndash160081 cmminus1 for C=C aromatic as shown in Table 2So based on the characterization using FTIR it can besaid that CMC-benzaldehyde from the synthesis results hasformed new functional groupwhich is imine (C=N) andC=Caromatic The shift of wave numbers in the FTIR spectrumof chitosan CMC and CMC-benzaldehyde in this study isshown in Figure 7

33 Mechanism of Corrosion Corrosion in the metal is anirreversible oxidation-reduction reaction occurring betweenthe metal and the oxidizing agent in an environment Thereare various chemicals in the environment that can acceleratethe occurrence of corrosion such as acidic salt and alkaline


3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

35

40

45

50

55

60

T

Figure 5 FTIR spectrum of chitosan

3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

01020304050607080

T

Figure 6 FTIR spectrum of CMC

Table 2 Analysis of new functional groups of CMC-benzaldehydeusing FTIR

Functionalgroups

Wave numbersaccording to Pretsch

et al (cmminus1)

Wave numbers ofCMC-benzaldehyde fromthe synthesis results (cmminus1)

C=N 1645 164131C=C aromatic 1600 1450ndash160081

substances The higher concentration of these substancescauses the corrosion rate of a metal to become faster

In this study HCl 1M is used as an oxidizing agent onsteel HCl 1M acts as an acid medium causing corrosionof steel so that the corrosion rate can become faster in arelatively short time Reactions that occur in this study canbe described as follows

Fe(s) + 2HCl(aq) 997888rarr FeCl2(aq) +H2(g) (4)

The redox reaction consists of two half-cell reactions Thesereactions are

Anode Fe 997888rarr Fe2+ + 2eCathode 2H+ + 2e 997888rarr H2

Fe + 2H+ 997888rarr Fe2+ +H2

(5)

The half-cell reaction of the anode and cathode showsthe exchange of electrons during the redox reaction process

T (

)

CMC-benzaldehid CMCChitosan

3000 2000 1000 04000Wave numbers (cＧminus1)

Figure 7 FTIR spectrum of chitosan CMC and CMC-benzaldehyde

The corrosion mechanism of carbon steel without CMC-benzaldehyde inhibitors provides an opportunity of H+ fromthe acid to be captured directly by the electrons that presentin the steel so that the corrosion rate becomes fast Steelwithout CMC-benzaldehyde inhibitors was used as a negativecontrol in this study Illustration of corrosionmechanisms onsteel without CMC-benzaldehyde inhibitors can be seen inFigure 8(a)

The corrosion mechanism of steel with CMC-benzaldehyde inhibitors gives the chance of H+ fromthe acid to be captured by the electrons present in the steelbecoming smaller due to the less direct contact that occurswith the addition of CMC-benzaldehydeThus the corrosionrate that occurs becomes slower when compared to thecorrosion rate without the addition of CMC-benzaldehydeAddition of CMC-benzaldehyde cannot cover all parts ofsteel This is because CMC-benzaldehyde is a polymer thathas an amorphous structure so that the coating on the steelstill provides pores that allow the occurrence of contactwith H+ Illustration of corrosion mechanisms on steel withCMC-benzaldehyde inhibitors can be seen in Figure 8(b)

Starch is added to CMC-benzaldehyde in order to coverthe pores that are still not covered completely It aims toreduce the contact between electrons on steel with H+Illustration of corrosion mechanisms on steel with CMC-benzaldehyde inhibitors and starch can be seen in Figure 8(c)

34 Effect of Addition of CMC-Benzaldehyde on CorrosionRate Addition of CMC-benzaldehyde to steel is done bydripping and coating methods and the corrosion rate of thesteel is carried out by potentiostatic polarization method Inthis study used variations in concentration on the addition ofCMC-benzaldehyde are 1 3 5 and 7 g for 60mL of solvent Inaddition in this study some treatments were added to starchof 01 gmL in CMC-benzaldehyde and some treatments were


Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)

Figure 8 Hypothesis of corrosion mechanisms for the following (a) without the addition of CMC-benzaldehyde inhibitors (b) with theaddition of CMC-benzaldehyde inhibitors and (c) with the addition of CMC-benzaldehyde and starch inhibitors

not added to starch Addition of starch aims to reduce poresthat are still not covered with CMC-benzaldehyde inhibitorso optimal results are expected

The negative control performed on steel without the addi-tion of CMC-benzaldehyde showed that the corrosive ratecaused by HCl 1M as corrosive medium was 589mmyearwith a corrosive current of 50689 120583Acm2

Dripping with CMC-benzaldehyde showed good resultswhere the corrosion rate and corrosion current decreasewith the concentration of CMC-benzaldehyde that has beengiven It also shows that the addition of CMC-benzaldehydecan cause the corrosion rate to be slower than without theaddition of CMC-benzaldehyde

Dripping with CMC-benzaldehyde and starch showedbetter results than dripping without the addition of starchIn dripping with CMC-benzaldehyde and starch corrosionrates and corrosion currents decreased dramatically withincreasing concentrations of CMC-benzaldehyde and starchthat has been given

And coating with CMC-benzaldehyde also showeddecreasing corrosion rate and corrosion current along withincreasing concentration of CMC-benzaldehyde that hasbeen given

Coating with CMC-benzaldehyde and starch also showeda decrease in corrosion rate and corrosion current alongwith the added concentration of CMC-benzaldehyde thathas been given In coating with CMC-benzaldehyde witha concentration of 7 g for 60mL of solvent gives very lowcorrosion rate and corrosion current value compared to othertreatments (dripping with CMC-benzaldehyde drippingwith CMC-benzaldehyde and starch and coating with CMC-benzaldehyde) The values of corrosion rate and corrosioncurrent are 00119mmyear and 10203120583Acm2 respectivelyThe effect of concentration of CMC-benzaldehyde with andwithout the addition of starch on the dripping and coatingmethods to the corrosion current and corrosion rate can beseen in Table 3

35 Surface Morphology of Steel In this study to determinethe type of corrosion that occurs on steel is done usingScanning Electron Microscope (SEM) The morphology ofthe steel surface as a result of corrosion can be seen clearlywhen compared with seeing with the naked eye Based onthe SEM results it can be seen that steel surfaces that havebeen added using CMC-benzaldehyde with and withoutstarch after potentiostatic polarization testing have resultedin carbon steel having pitting corrosion The analysis resultsof surfacemorphology using SEM for steel after potentiostaticpolarization testing can be seen in Figure 9

36 Inhibition Efficiency of CMC-Benzaldehyde against Cor-rosion Rate Based on the calculated data of inhibitionefficiency the highest efficiency value to inhibit the corrosionrate is shown by coating method with CMC-benzaldehydeconcentration of 7 g60mL of solvent and starch of 01 gmLis 998 This indicates that CMC-benzaldehyde is able toinhibit corrosion rate of 998 and there is corrosion rateof 02 which can still occur in the steel that has beengiven treatment by adding CMC-benzaldehyde and starchInhibition efficiency from the results of research that hasbeen done by dripping and coating methods using CMC-benzaldehyde with and without starch can be seen in Table 3

In the research that has been done by Erna et al [12]the efficiency of corrosion inhibition of CMC for steels inwater gives optimum results at pH 5 and CMC concentrationof 1 ppm is 77 While in this study the use of CMC-benzaldehyde gives optimum results at concentration of7 g60mL of solvent and the addition of starch as much as01 gmL in HCl 1M with pH 253 is 998

In addition based on research that has been done by Fins-gar and Jackson [13] the efficiency of CMC-benzaldehyde canalso be compared with the use of other corrosion inhibitorsin the oil and gas industry as the use of NN1015840-ortho-phenylenacetyle acetone imine with concentrations of 50ndash400mgL inHCl 1Mgives inhibitory efficiency of 249ndash826However


Table 3 The effect of concentration of CMC-benzaldehyde with and without the addition of starch on the dripping and coating methods tothe corrosion current corrosion rate and inhibition efficiency

Treatment Concentration(g60mL of solvent)

Corrosion current(120583Acm2)

Corrosion rate(mmyear)

Efficiency of inhibitor()

Negative control - 50689 58900 -

Dripping withCMC-benzaldehyde

1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413

Dripping withCMC-benzaldehyde andstarch

1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956

Coating withCMC-benzaldehyde

1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711

Coating withCMC-benzaldehyde andstarch

1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone

(b)Figure 9 The analysis results of surface morphology using SEM for steel surfaces that have been added using (a) CMC-benzaldehyde withstarch and (b) CMC-benzaldehyde without starch after potentiostatic polarization (coating method concentration of 7 g60mL)

in this study the efficiency of CMC-benzaldehyde in the steelswith concentrations of 1 g60mL of solvent to 7 g60mL ofsolvent by dripping and coating methods with and withoutstarch in HCl 1M gives corrosion efficiency with range of2019ndash998

4 Conclusion

Based on the research that has been done and the dataobtained it can be concluded that CMC-benzaldehyde canbe used as anticorrosion agent on steel The effect of con-centration on the corrosion rate of steel is that the higherconcentration of CMC-benzaldehyde canmake the corrosionrate on steel become slower Conversely the smaller CMC-benzaldehyde concentration that has been used makes thecorrosion rate on steel become fasterThe highest efficiency toinhibit corrosion rate on steel is 998 which can be obtained

by coating method using CMC-benzaldehyde with concen-tration of 7 g60mL of solvent and starch of 01 gmL Theuse of CMC-benzaldehyde inhibitors with concentrations of1 g60mL of solvent to 7 g60mL of solvent gives corrosionefficiency with range of 2019ndash998

Disclosure

The paper was represented as an abstract which is part ofundergraduate thesis and can be seen in the link httprepositoryunairacid282311gdlhub-gdl-s1-2014-anggara-leo-37493-5-abstr-kpdf

Conflicts of Interest

The authors declare no competing financial interests


References

[1] A Gunaatmaja Pengaruh Waktu Perendaman terhadap LajuKorosi pada Baja Karbon Rendah dengan Penambahan EkstrakUbi Ungu sebagai Inhibitor Organik di Lingkungan NaCl 35Universitas Indonesia Java Indonesia 2011

[2] K R Trethewey and J Chamberlain Corrosion for Students ofScience and Engineering Longman Scientific amp Technical NewYork NY USA 1988

[3] R W Revie and H H Uhlig Corrosion and Corrosion ControlAn Introduction to Corrosion Science and Engineering JohnWiley amp Sons Hoboken New Jersey USA 4th edition 2008

[4] F R de Abreu and S P Campana-Filho ldquoCharacteristics andproperties of carboxymethylchitosanrdquo Carbohydrate Polymersvol 75 no 2 pp 214ndash221 2009

[5] X Xue L Li and J He ldquoThe performances of carboxymethylchitosan in wash-off reactive dyeingsrdquo Carbohydrate Polymersvol 75 no 2 pp 203ndash207 2009

[6] F S de Souza and A Spinelli ldquoCaffeic acid as a green corrosioninhibitor for mild steelrdquo Corrosion Science vol 51 no 3 pp642ndash649 2009

[7] M Zheng B Han Y Yang and W Liu ldquoSynthesis characteri-zation and biological safety of O-carboxymethyl chitosan usedto treat Sarcoma 180 tumorrdquoCarbohydrate Polymers vol 86 no1 pp 231ndash238 2011

[8] X-G Chen and H-J Park ldquoChemical characteristics of O-carboxymethyl chitosans related to the preparation conditionsrdquoCarbohydrate Polymers vol 53 no 4 pp 355ndash359 2003

[9] T F Jiao J Zhou L Gao Y Y Xing and X Li ldquoSynthesis andcharacterization of chitosan-based schiff base compounds witharomatic substituent groupsrdquo Iranian Polymer Journal vol 20no 2 pp 123ndash136 2011

[10] W D Callister Material Science and Engineering An Introduc-tion Wiley New York NY USA 1985

[11] E Pretsch Th Clerc J Seibl and W Simon Tables of Spec-tral Data for Structure Determination of Organic CompoundsSpringer-Verlag Berlin Heidelberg Berlin Germany 2nd edi-tion 1989

[12] M Erna E Emriadi A Alif S Arief and M J NoordinldquoSintesis dan aplikasi karboksimetil kitosan sebagai inhibitorkorosi pada baja karbon dalam airrdquo Jurnal Natur Indonesia vol12 no 1 pp 87ndash92 2009

[13] M Finsgar and J Jackson ldquoApplication of corrosion inhibitorsfor steels in acidic media for the oil and gas industry A reviewrdquoCorrosion Science vol 86 pp 17ndash41 2014

International Journal of

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Volume 2018

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There are various efforts of metal protection to overcomecorrosion among others surface coating and cathode pro-tection systems require a high cost because of the selectionof inhibitors used The effort has also not been effective inovercoming corrosion In this research corrosion inhibitorfrom organic material as anticorrosion is usedThis inhibitoris chosen because it has a high affinity on the metal withhigh efficiency and being friendly to the environment Thecorrosion inhibitor used is namely carboxymethyl chitosan(CMC) which is substituted with benzaldehyde

Carboxymethyl chitosan (CMC) is a derivative of chi-tosan derived from chitin isolated from terrestrial inverte-brates marine invertebrates and fungi which are numerousin nature In invertebrates chitin serves as an exoskeletoncomposite matrix whereas in fungi it functions as a cell wallshaper Chitosan is a soluble solid in acetic acid and easilydegraded but the application of chitosan is limited because itis not water soluble [4]

The use of CMC in this study is preferred over chitosanitself This is because CMC has an important characteristicthat is water soluble high gel forming capacity low toxicityand good biocompatibility so that the application will bewider [5] In addition CMC is widely used because it isamphiprotic which contains the -COOH and -NH2 groupsin its molecules that have many free electron pairs

In this study the -NH2 group present in CMC (actingas base) is substituted with benzaldehyde to form car-boxymethyl chitosan-benzaldehyde (CMC-benzaldehyde)compound These compounds are expected to be used as aneffective and effective anticorrosion in inhibiting the corro-sion rate on steel CMC-benzaldehyde is used as a corrosioninhibitor due to the presence of heteroatoms (O and N) thephi bond formed between CMC and benzaldehyde and thenumber of free electrons that can support the inhibitor inchemisorption with the metal by coordination [6]

Therefore in this study the inhibition of corrosion ratewas carried out on the steel in the medium of HCl 1Musing the CMC-benzaldehyde inhibitor The method usedto determine the corrosion rate is the measurement of theintensity of corrosion current on steel with potentiostaticpolarization

2 Materials and Methods

21 Materials and Tools The materials used in this studywere chitosan from Good Manufacturing Practice glacialacetic acid NaOH chloroacetic acid isopropanol ethanol998 distilled water double-distilled water benzaldehydecommercial steel filter paper cassava andHCl 37while thetool used in this research is Fourier Transform Infrared Spec-trometer (FTIR) SHIMADZU Potentiostat PGSTAT302Ncorrosion test instrument coupled with computer and Auto-lab NOVA software and SEM-EDX Carl Zeiss EVOMA 10

22 Synthesis of CMC and CMC-Benzaldehyde

221 Synthesis of CMC A total of 10 g of chitosan wasdissolved in 400mL of acetic acid 2 The soluble chitosanwas added to 135 g of NaOH and was reacted over the water

bath at 50∘C for 1 hour The solution was refluxed and addedto 15 g of chloroacetic acid which has been dissolved in 20mLof isopropanol The mixture was reacted for 4 hours at 50∘CThe treated mixture was filtered off with a Buchner funneland washed with ethanol 70 The obtained precipitate isdried at room temperatureThe result is a CMCwhich is thencharacterized using FTIR [8]

222 Synthesis of CMC-Benzaldehyde A total of 20 g ofCMCwas dissolved in 400mL of distilled waterThe solutionwas reacted with benzaldehyde-ethanol with a ratio of 1 1(5mL of benzaldehyde mixed with 5mL of ethanol) Thetemperature used during the reaction takes approximately50ndash60∘C The reaction was carried out for 5 hours and thenfiltrate and the precipitate was filtered using a Buchner funneland washed with ethanol 70 The precipitate obtained isthe result of the synthesis of CMC-benzaldehyde CMC-benzaldehyde obtained was characterized using FTIR [9]

23 Preparation of Starch A total of 1 kg of cassava is cleanedand peeled Then the cassava is smoothed using a grinderFinely ground cassava is then soaked in distilled water for24 hours The filtrate and the precipitate are separated bydecantation The precipitate obtained is dried to obtain astarch made from cassava A total of 5 g of starch wasdissolved in 50mL of hot aquades by stirring until a homoge-neous solution was obtained This formed starch solution ismixed in CMC-benzaldehyde

24 Treatment for Steel The steel used in this study wascleaned by sand and cut with length of 20mm width of10mm and thick of 1mmThe chemical composition contentof the steel was tested using EDX (Energy Dispersive X-Ray)analysis

25 Testing of Corrosion Rate on Steel in HCl 1M

251 Testing of Corrosion Rate on Steel without Addition ofCMC-Benzaldehyde The steel is first immersed in 100mLof HCl 1M for 120 hours After the corrosion process runsduring that time the steel is taken and washed with double-distilled water Furthermore the steel is left for a while andthen heated in an oven at a temperature of 45ndash50∘C for10 minutes Testing of corrosion rates on steels in HCl 1Mwithout addition of CMC-benzaldehyde was performed bypotentiostatic polarization method as shown in Figure 1

252 Testing of Corrosion Rate on Steel with the Additionof CMC-Benzaldehyde Tests of corrosion rates on steels inHCl 1M were carried out with two treatments drippingand coating wherein each treatment was added to CMC-benzaldehyde without starch and with starch Drippingwith the addition of CMC-benzaldehyde was performed bydissolving CMC-benzaldehyde of 1 g 3 g 5 g and 7 g in amixture of 20mL of distilled water 20mL of acetic acid2 and 20mL of alcohol at a ratio of 1 1 1 Subsequentlya 100mL of HCl 1M was added to the solution of CMC-benzaldehyde by stirring until homogeneous The solution is


IE

E Potentiostat

RE

CEWE







Corrosioncurrent

CZ CZPotential (V)

c

Log

of in

tens

ity (m

A)





(1)





HCl


（Ｆ（2（


O

H

H

OH

OHH

H

O

H

（2

（2

O

H

H

OH

OHH

H

O

H

（2

（2

（2

O

H

H

OH

OHH

H

O

H

（2



119868corr =120573119888 times 120573120572

















O

HH

OH

OHH

H

O

H

H

CMC Benzaldehyde

+O

NHHH

OH

OHH

H

O

H

CHH

O

HH

OH

OHH

H

O

H

CHHO

O

HH

OH

OHH

H

O

H

CHO

H

H

O

NHH

OH

OHH

H

O

H

CH

H

O

NHH

OH

OHH

H

O

H

CH

CMC-benzaldehyde

（2H（2H（2H

（2H （2H （2H

minus（2O

oplus

Hoplus

minusHoplus

oplus

oplus

⊖

（∙∙

2（∙∙

（∙∙

O∙∙

∙ ∙

O∙∙

∙ ∙













3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

35

40

45

50

55

60

T


3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

01020304050607080

T



Functionalgroups


et al (cmminus1)








Fe + 2H+ 997888rarr Fe2+ +H2

(5)


T (

)









Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)




















1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



IE

E Potentiostat

RE

CEWE







Corrosioncurrent

CZ CZPotential (V)

c

Log

of in

tens

ity (m

A)





(1)





HCl


（Ｆ（2（


O

H

H

OH

OHH

H

O

H

（2

（2

O

H

H

OH

OHH

H

O

H

（2

（2

（2

O

H

H

OH

OHH

H

O

H

（2



119868corr =120573119888 times 120573120572

















O

HH

OH

OHH

H

O

H

H

CMC Benzaldehyde

+O

NHHH

OH

OHH

H

O

H

CHH

O

HH

OH

OHH

H

O

H

CHHO

O

HH

OH

OHH

H

O

H

CHO

H

H

O

NHH

OH

OHH

H

O

H

CH

H

O

NHH

OH

OHH

H

O

H

CH

CMC-benzaldehyde

（2H（2H（2H

（2H （2H （2H

minus（2O

oplus

Hoplus

minusHoplus

oplus

oplus

⊖

（∙∙

2（∙∙

（∙∙

O∙∙

∙ ∙

O∙∙

∙ ∙













3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

35

40

45

50

55

60

T


3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

01020304050607080

T



Functionalgroups


et al (cmminus1)








Fe + 2H+ 997888rarr Fe2+ +H2

(5)


T (

)









Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)




















1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



HCl


（Ｆ（2（


O

H

H

OH

OHH

H

O

H

（2

（2

O

H

H

OH

OHH

H

O

H

（2

（2

（2

O

H

H

OH

OHH

H

O

H

（2



119868corr =120573119888 times 120573120572

















O

HH

OH

OHH

H

O

H

H

CMC Benzaldehyde

+O

NHHH

OH

OHH

H

O

H

CHH

O

HH

OH

OHH

H

O

H

CHHO

O

HH

OH

OHH

H

O

H

CHO

H

H

O

NHH

OH

OHH

H

O

H

CH

H

O

NHH

OH

OHH

H

O

H

CH

CMC-benzaldehyde

（2H（2H（2H

（2H （2H （2H

minus（2O

oplus

Hoplus

minusHoplus

oplus

oplus

⊖

（∙∙

2（∙∙

（∙∙

O∙∙

∙ ∙

O∙∙

∙ ∙













3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

35

40

45

50

55

60

T


3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

01020304050607080

T



Functionalgroups


et al (cmminus1)








Fe + 2H+ 997888rarr Fe2+ +H2

(5)


T (

)









Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)




















1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



O

HH

OH

OHH

H

O

H

H

CMC Benzaldehyde

+O

NHHH

OH

OHH

H

O

H

CHH

O

HH

OH

OHH

H

O

H

CHHO

O

HH

OH

OHH

H

O

H

CHO

H

H

O

NHH

OH

OHH

H

O

H

CH

H

O

NHH

OH

OHH

H

O

H

CH

CMC-benzaldehyde

（2H（2H（2H

（2H （2H （2H

minus（2O

oplus

Hoplus

minusHoplus

oplus

oplus

⊖

（∙∙

2（∙∙

（∙∙

O∙∙

∙ ∙

O∙∙

∙ ∙













3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

35

40

45

50

55

60

T


3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

01020304050607080

T



Functionalgroups


et al (cmminus1)








Fe + 2H+ 997888rarr Fe2+ +H2

(5)


T (

)









Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)




















1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

35

40

45

50

55

60

T


3600 3200 2800 2400 2000 1600 1200 800 4004000(1cm)

01020304050607080

T



Functionalgroups


et al (cmminus1)








Fe + 2H+ 997888rarr Fe2+ +H2

(5)


T (

)









Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)




















1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



Carbon steel

（+

2+

2+

2+

minus

minus

minus

minus

(a)

2+

2+

Carbon steel

CMC-benzaldehyde

（+

minus

minus

minus

(b)

Carbon steel

CMC-benzaldehyde

Starch

2+

（+

minus

minus

(c)




















1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia










1 23497 27303 53653 15788 18346 68855 14221 16525 71947 13113 15237 7413


1 40455 47008 20193 20964 24360 58645 49576 00576 99027 22381 00260 9956


1 38848 45141 23363 36521 42437 27955 79701 09261 84287 14661 01704 9711


1 35353 41080 30253 29871 34710 41075 25404 00295 99507 10203 00119 9980

Corrosion zone

CMC-benzaldehyde

(a)

Corrosion zone



4 Conclusion



Disclosure





References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia



References
















RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia




RoboticsJournal of




VLSI Design



Shock and Vibration







Journal of



Volume 2018



Volume 2018


Journal of




SensorsJournal of



RotatingMachinery





Propagation






Hindawi


Advances in

Multimedia


Application of Carboxymethyl Chitosan-Benzaldehyde as...

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Transcript of Application of Carboxymethyl Chitosan-Benzaldehyde as...