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Zaštita materijala 1 2011

ZAŠTITA MATERIJALA 2011 52(1) 3-19     Review the paper [PDF]

M. SANGEETHA1, S. RAJENDRAN1, T. S. MUTHUMEGALA1, A. KRISHNAVENI2


1
Corrosion Research centre, P.G. and Research Department of Chemistry, GTN Arts college, Dindigul – 624005, India
2Corrosion Research centre, Department of Chemistry, Yadava college, Madurai-India

Green corrosion inhibitors – An Overview
Abstract:
To replace the environmentally hazardous chromates, several non–chromates have been used as corrosion inhibitors. Extracts of plant materials top the list. The plant extracts are environmentally friendly, non- toxic and readily available. These extracts contain many ingredients. They contain several organic compounds which have polar atoms such as O, N, P and S. They are adsorbed onto the metal surface through these polar atoms; protective films are formed. Adsorptions of these ingredients obey various adsorption isotherms. The films have been analyzed by many surface analysis techniques such as AFM, FTIR, UV, Fluorescence spectra and SEM.


ZAŠTITA MATERIJALA 2011 52(1) 21-34                 Scientific Paper [PDF]

A. S. FOUDA1, AHMED ABDEL NAZEER2, E. A. ASHOUR2

1Department of Chemistry, Faculty of Science, El-Mansoura University, El- Mansoura-35516, Egypt
2Electrochemistry and Corrosion Lab., National Research Centre, Dokki, Cairo-12622, Egypt

Amino acids as environmentally-friendly corrosion inhibitors for Cu10Ni alloy in sulfide-polluted salt water: Experimental and theoretical study

Abstract: The inhibition effect of three amino acids ( valine (val), alanine (ala) and glycine (gly)) on the corrosion of Cu10Ni alloy in sulfide-polluted salt water (3.5 % NaCl + 16ppm S2-) was studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), scanning electron microscopy (SEM) and energy dispersive X-ray diffraction (EDX). The polarization measurements showed that the tested compounds act as mixed-type inhibitors. Results obtained from the different techniques reveal that the inhibition efficiency (%IE) follows the sequence: val > ala > gly. A synergistic effect was observed between these inhibitors and KI. SEM showed a remarkable inhibiting effect of these additives due to the protective film formed on the alloy surface confirmed by the presence of the carbon and nitrogen atoms in the EDX spectra. The adsorption of these inhibitors was found to be of a physisorption mode and obeys Langmuir’s adsorption isotherm. Some quantum chemical parameters were calculated by the MNDO Semi-empirical method to provide further insight into the mechanism of inhibition of the corrosion process.


ZAŠTITA MATERIJALA 2011 52(1) 35-41              Scientific paper [PDF]

S. RAJENDRAN1, T.S. MUTHUMEGALA1, A. KRISHNAVENI2, M. MANIVANNAN3, B. SHYAMALA DEVI4, B. NARAYANA SAMY5, N. HAJARA BEEVI6, A LEEMA ROSE7


1Corrosion Research Centre, Post Graduate and Research Department of Chemistry, GTN Arts College, Dindigul-624 005, Tamilnadu, India
2Department of Chemistry, Yadava College, Madurai, India
3Department of Chemistry, Chettinad College of Engineering and Technology, Karur, India
4Department of Chemistry, Vivekanandha Institute of Engineering and Technology, Thiruchengode, Tamil Nadu, India
5Department of Chemistry, Theigarajar College of Enginnering, Madurai, India
6Department of Chemistry, B.S. Abdur Rahman University, Vandalur, Chennai – 600 048, India
7Department of Chemistry, Holy Cross College, Trichy, India

Corrosion behaviour of mild steel in simulated concrete pore solution
Abstract:
The corrosion resistance  of  three metals, namely, mild steel (MS) galvalnised steel (GS) and SS 316L, in simulated concrete pore solution, namely, saturated calcium hydroxide solution has keen evaluated by electrochemical studies such as polarization study and AC impedance spectra.  The corrosion resistance of the metals in simulated concrete pore solution is SS 316 L > GS > MS.


ZAŠTITA MATERIJALA 2011 52(1) 43-48               Scientific paper [PDF]

SUZANA CAKIC1, CASLAV LACNJEVAC2, MILOS RAJKOVIC2, LJILJANA RASKOVIC1, JAKOV STAMENKOVIC1


1Faculty of Technology, Leskovac, Bulevar Oslobođenja 124
2Faculty of Agriculture, Zemun, Nemanjina 6, Serbia

 

Reticulation of aqueous polyurethane systems
Abstract:
The DSC method has been employed to monitor the kinetics of reticulation of aqueous polyurethane systems without catalysts, and with the commercial catalyst of zirconium (CAT®XC-6212) and the highly selective manganese catalyst, the complex Mn (III)-diacetylacetonemaleinate (MAM). Among the polyol components, the acrylic emulsions were used for reticulation in this research, and as suitable reticulation agents the water emulsible aliphatic polyisocyanates based on hexamethylendoisocyanate with the different contents of NCO-groups were employed. On the basis of DSC analysis, applying the methods of Kissinger, Freeman-Carroll and Crane-Ellerstein the pseudo kinetic parameters of the reticulation reaction  of aqueous systems were determined. The temperature range of the examination was from 500 to 4500 ºC with the heat rate of 0.50 ºC/min. The reduction of the activation energy and the increase of the standard deviation indicate the catalytic action of the selective catalysts of zirconium and manganese. The impact of the catalysts on the reduction of the activation energy is the strongest when using the catalysts of manganese and applying all the three afore-said methods. The least aberrations among the stated methods in defining the kinetic parameters   were obtained   by using the manganese catalyst.


ZAŠTITA MATERIJALA 2011 52(1) 49-54                            Stručni rad [PDF]

SLAĐANA Č. ALAGIĆ, SNEŽANA M. UROŠEVIĆ , MILOVAN V. VUKOVIĆ


Univerzitet u Beogradu, Tehnički fakultet, Bor, Vojske Jugoslavije 12

Rizici od upotrebe dekabrom difenil etra i moguće zamene u tekstilnoj industriji
Izvod:
Upotreba dekabromdifenil etra je jeftina i izuzetno pouzdana metoda za tretiranje tekstila radi zaštite od vatre i gorenja. Međutim, povećana zabrinutost stručne i naučne  javnosti o njegovim potencijalnim negativnim uticajima na stanje životne sredine i ljudskog zdravlja, uslovila je potragu za drugim hemikalijama koje mogu biti pogodna zamena, tj supstitucija ovom organobromnom usporivaču gorenja. U slučaju tekstila, zbog kompleksnosti proizvoda, načini supstitucije nisu tako jednostavni. Danas se najčešće pristupa upotrebi drugih usporivača gorenja, manje opasnih po ljudsko zdravlje, kao i upotrebi alternativnih potpuno vatro-otpornih vlakana i njihovih mešavina.


ZAŠTITA MATERIJALA 2011 52(1) 55-60                                  Stručni rad [PDF]

DRAGAN UGRINOV1, ALEKSANDER STOJANOV2


1Zavod za javno zdravlje Pančevo, Pasterova 2
2Direkcija za građevinsko Zemljište i izgradnju, J. P., Beograd, Njegoševa 84

Upravljanje medicinskim otpadom, kao kategorijom opasnog otpada
Izvod
: U modernom društvu gotovo sve što nas okružuje i što koristimo postaje nakon nekog vremena neupotrebljivo i prelazi u otpad. U prirodnim tokovima materija i energija se gotovo uvek ponovo koriste u lancima ishrane, tako da ti ciklusi kruženja ne produkuju nikakav otpad. Razvojem novih tehnologija čovek je stvorio niz sintetskih materijala koji se nikada nisu pojavili u prirodi i za koje sama priroda nema rešenja. Svaka institucija pa i osoba je proizvođač neke vrste otpada. Zdravstvene ustanove u svom radu proizvode različite vrste otpada koje ako se ne zbrinu na kvalitetan način mogu teško zagaditi životnu sredinu i predstavljaju opasnost za zaposlene, korisnike zdravstvenih usluga, posetioce kao i za lica koja neovlašteno rukuju sa otpadom. Opasan medicinski otpad zahteva posebne metode obrade i konačnog odlaganja.


ZAŠTITA MATERIJALA 2011 52(1) 61-67                      Stručni rad [PDF]

ALEKSANDER STOJANOV1, DRAGAN UGRINOV2


1Direkcija za građevinsko Zemljište i izgradnju, J. P., Beograd, Njegoševa 84
2
Zavod za javno zdravlje Pančevo, Pasterova 2

Istorijski pregled u tretmanu otpadnih voda
Izvod
: U radu je dat istorijski pregled problematike sa otpadnim vodama u Velikoj Britaniji i Nemačkoj, gde se mogu videti početni koraci u identifikaciji uzročnika bolesti, kao i začetci postupaka za detekciju i tretman otpadnih voda(industrijskih i komunalnih).Sredinom 19.-og veka postojala su pitanja na koja je trebalo dati adekvatne odgovore: Koliko je prljava otpadna voda u odnosu na specifična jedinjenja ili ukupne parametre; i kako mogu izmeriti ove parametre ili koncentraciju ovih specifičnih jedinjenja? Gde je najbolje mesto za uzimanje uzorka za analizu iz reke ili iz postrojenja za tretman otpadnih voda?