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Zaštita materijala 1. 2019

 

Abdel Aziz Fouda*1, Salah Mohmed Rashwan2, Mona Abdelfatah1

1El-Mansoura University, Department of Chemistry, Faculty of Science, El-Mansoura-35516, Egypt, 2Suez Canal University, Department of Chemistry, Faculty of Science, Ismailia,  Egypt

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:620.197.3
doi: 10.5937/zasmat1901003F

Zastita Materijala 60 (1)
3 – 17  (2019)

Corrosion Inhibition of stainless steel 304 in hydrochloric acid solution using clindamycin antibiotic as Eco-friendly inhibitor

Abstract

The corrosion protection of stainless steel 304 (SS 304) in 2M HCl solutions using Clindamycin antibiotic was investigated by weight loss (WL), electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) tests. Electrochemical results showed that this compound is an efficient inhibitor for SS304 and the efficiency reached 93 % at 300 ppm. The inhibition efficiency (IE) increases with the drug concentration and decreases with rising temperature. Data from electrochemical measurements suggested that the drug functioned by adsorption of the molecule on the metal/corroding interface, inhibiting both the cathodic and anodic half-reactions of the corrosion process. The adsorption of this drug on SS304 surface follows Langmuir adsorption isotherm. The thermodynamic functions of activation and adsorption processes were calculated and discussed. The surface morphology of the SS304 specimens was evaluated using atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).

Keywords: SS 304, Corrosion inhibition, HCl, AFM, FTIR, Clindamycin antibiotic.

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Inhibicija korozije nerđajućeg čelika 304 u rastvoru hlorovodonične kiseline korišćenjem antibiotika klindamicina kao ekološkog inhibitora

Zaštita od korozije nerđajućeg čelika 304 (SS 304) u 2M rastvorima HCl pomoću klindamicin antibiotika ispitivana je gubitkom težine (VL), postupkom elektrokemijske modulacione frekvencije (EFM), elektrokemijskom impedansnom spektroskopijom (EIS) i potenciodinamičkom polarizacijom (PP). Elektrohemijski rezultati su pokazali da je ovo jedinjenje efikasan inhibitor za nerđajući čelik SS304 i da je efikasnost dostigla 93% na 300 ppm. Efikasnost inhibicije (IE) se povećava sa koncentracijom leka i opada sa porastom temperature. Podaci iz elektrokemijskih merenja ukazuju da je lek funkcionisao adsorpcijom molekula na granici metal / korodent, inhibirajući i katodnu i anodnu polu reakciju procesa korozije. Adsorpcija ovog leka na površini SS304 prati izotermijsku adsorpciju Langmira. Proračunate su i diskutovane termodinamičke funkcije procesa aktivacije i adsorpcije. Morfologija površine SS304 uzoraka je procenjena korišćenjem mikroskopije (AFM) i infracrvene spektroskopije Fourier-ove transformacije (FTIR).

Ključne reči: SS 304, inhibicija korozije, HCl, AFM, FTIR, klindamicin antibiotic.

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Ilija Bobić1, Bore Jegdić2, Biljana Bobić2*

1University of Belgrade, “Vinča” Institute of Nuclear Sciences, Belgrade, Serbia, 2University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:620.197.7
doi:10.5937/zasmat1901018B


Zastita Materijala 60 (1)
18 – 25  (2019)

The resistance to general corrosion of series of zinc-aluminum alloys modified with silicon and strontium

Abstract

The resistance to corrosion of the series of zinc-aluminum casting alloys modified with silicon and strontium was studied in a sodium chloride solution. It was shown that general corrosion was the main form of corrosion of Zn25Al-Si-Sr alloys in the test solution. The corrosion process takes place through the anodic dissolution of the alloys, while the cathodic reaction is controlled by diffusion of oxygen in the test solution. Three different electrochemical techniques were applied to determine the corrosion current density, which is the electrochemical indicator of corrosion rate. The value of corrosion current density for each Zn25Al-Si-Sr alloy was calculated using the value of polarization resistance, obtained by electrochemical impedance spectroscopy or by linear polarization resistance technique. The value of corrosion current density was also determined directly from Tafel plots, which were recorded by linear sweep voltammetry. As the content of silicon and strontium in the tested alloys increases, the value of corrosion current density increases gradually. The results obtained by different electrochemical techniques are in good agreement.

Keywords: zinc-aluminum alloys, corrosion rate, electrochemical techniques.

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Otpornost na opštu koroziju serije legura cink-aluminijum  koje su modifikovane silicijumom i stroncijumom

Izvod

Otpornost na koroziju serije legura cink-aluminijum za livenje, koje su modifikovane silicijumom i stroncijumom, ispitana je u rastvoru natrijum hlorida. Pokazano je da je opšta korozija glavni oblik korozije Zn25Al-Si-Sr legura u navedenom rastvoru. Proces korozije odvija se kao anodno rastvaranje legura, dok je katodna reakcija kontrolisana difuzijom kiseonika u rastvoru. Tri različite elektrohemijske tehnike primenjene su za određivanje gustine struje korozije, koja je elektrohemijski pokazatelj brzine korozije. Vrednost gustine struje korozije za svaku Zn25Al-Si-Sr leguru izračunata je na osnovu vrednosti polarizacione otpornosti, koja je određenai spektroskopijom elektrohemijske impedanse ili tehnikom linearne polarizacije. Vrednost gustine struje korozije je takođe određena direktno iz Tafelovih dijagrama, koji su registrovani pomoću voltametrije sa linearnom promenom potencijala. Sa povećanjem sadržaja silicijuma i stroncijuma u ispitivanim legurama vrednost gustine struje korozije postepeno raste. Rezultati dobijeni različitim elektrohemijskim tehnikama su u dobroj saglasnosti.

Ključne reči: legure cink-aluminijum, korozija, brzina korozije, elektrohemijske tehnike.

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Sanja Petronić1, Dubravka Milovanović1, Andjelka Milosavljević2, Željko Radovanović3, Olivera Erić-Cekić4*,
Radomir Jovičić4

1Univerzitet u Beogradu, Institut za nuklearne nauke “Vinča”, Beograd, Srbija, 2Univerzitet u Beogradu, Mašinski fakultet, Beograd, Srbija, 3Univerzitet u Beogradu, Tehnološko-metalurški fakultet u Beogradu, Beograd, Srbija, 4Inovacioni centar Mašinskog fakulteta u Beogradu, Beograd, Srbija

Pregledni rad
ISSN 0351-9465, E-ISSN 2466-2585
UDC:620.197.5:669.018.1
doi:10.5937/zasmat1901026P

Zastita Materijala 60 (1)
26 – 43  (2019)

Laserske obrade superlegure Nimonik 263

Izvod

U ovom radu, proučavan je uticaj parametara određenih procesa laserske tehnike obrade materijala superlegure Nimonic 263 – bušenje, rezanje, zavarivanje i mehanička obrada laserom. Bušenje i zavarivanje su vršeni na laseru Nd:YAG laserom model HTS Mobile LS-P160. Prilikom bušenja rupa varirani su parametri frekvencije impulsa (5 Hz, 7Hz i 9 Hz) i dužine trajanja impulsa (1,8 ms do 3,6 ms). Ispitivana je mikrostruktura i određene su geometrijske i metalurške karakteristike rupa dobijenih ovim parametrima, na osnovu čega je izvršena optimizacija parametara obrade. Rezanje je izvedeno na laseru tipa Bistronic laser, (2000), BISTAR 3015. Varirani su parametri srednje snage lasera, brzina lasera, pritisak gasa i položaj fokusa. Na osnovu dobijenih geometrijskih karakteristika rezova i površinske morfologije diskutovani su i određeni optimalni parametri. Laserom zavareni spojevi limova legure Nimonik 263 su, osim mikroskopskih i profilometrijskih ispitivanja površina, ispitivani i metodom sa razaranjem. Prilikom laserskog deformacionog ojačavanja uzorci su bili izloženi laserskom svetlu na talasnoj dužini od 1064 nm i 532 nm, sa brojem akumuliranih impulsa: 50, 100 i 200. U svim delovima eksperimenta strukturna analiza superlegure Nimonic 263 izvedena je pomoću svetlosne mikroskopije (SM), skenirajuće elektronske mikroskopije (SEM) i EDS-analize. Merenja mikrotvrdoće vršena su pomoću metode Vikersa pod opterećenjem od 9,81N. Profilometrija je izvedena na beskontaktnom profilometru Zygo NewView 7100.

Ključne reči: laserska obrada, Nimonik 263, EDS, mikotvrdoća, profilometrija.

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Laser treatments of NImonic 263 nickel-based superalloy

Abstract

In this paper, the influence of  parameters of laser processing (drilling, cutting, welding and laser shock peening) on microstructure of superalloy Nimonic 263 are investigated. Drilling and welding process are carried out on the Nd: YAG laser model LS-HTS Mobile P160. When drilling the holes, the parameters of pulse frequency (5 Hz, 7 Hz and 9 Hz) and the pulses duration (1.8 ms to 3.6 ms) are varied. The microstructure is investigated and geometrical and metallurgical characteristics of the holes are determined.Cutting is carried out on the laser BISTRONIC, (2000), BISTAR 3015. The parameters that were varied are as follows: the average laser power, laser velocity, the pressure of the assisting gas and the focus position. Based on the geometrical characteristics of the cuts and surface morphology the optimal parameters are discussed and defined. The laser welded joints of Nimonic 263, in addition to microscopic examination and surface profilometry, were subjected to the destructive testing. During the laser shock peening, the samples were exposed to laser light at a wavelength of 1064 nm and 532 nm, with the number of accumulated pulses 50, 100 and 200. The operating laser was Nd: YAG EKSPLO, SL212P model. Structural analysis of Nimonic 263 was carried out using light microscopy, scanning electron microscopy and EDS analysis. Microhardness measurements were carried out using the Vickers method under load of 9,81N. Profilometry was performed on a contactless profilometer Zygo Newview 7100.

Keywords: laser treatment, Nimonic 263, EDS microhardness, profilometry.

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Mihailo Mrdak1*, Časlav Lačnjevac2, Marko Rakin3, Nikola Bajić4, Darko Veljić4

1Istraživački i razvojni Centar, IMTEL komunikacije a.d., Beograd, Srbija, 2Univerzitet u Beogradu, Poljoprivredni fakultet, Beograd, Srbija, 3Univerzitet u Beogradu, Tehnološko-metalurški fakultet, Beograd, Srbija, 4Techno experts d.o.o – Istraživački i razvojni Center, IHIS, Beograd, Srbija

Naučni rad
ISSN 0351-9465, E-ISSN 2466-2585
UDC:620.193.8.197.5
doi:10.5937/zasmat1901044M


Zastita Materijala 60 (1)
44 – 49  (2019)

Karakterizacija plazma sprej bioinertne prevlake Al2O328tež.%MgO

Izvod

U ovom radu su prikazani rezultati ispitivanja mehaničkih i strukturnih karakteristika plazma sprej prevlake Al2O328tež.%MgO. Metalni oksid MgO u kompleksnom oksidu Al2O328tež.%MgO modifikuje osobine Al2O3 keramike formiranjem spinela MgAl2O4 odličnih biomedicinskih karakteristika. Slojevi prevlake su deponovani atmosferski plazma sprej procesom (APS) na čeličnim podlogama od nerđajućeg čelika X15Cr13 (EN 1.4024). Cilj ovog rada je bio da se ispita efekat jačine plazma struje (700A, 800A i 900A) na mehaničke osobine prevlake Al2O3MgO, sadržaj pora i mikrostrukturu slojeva. Ispitivanja mikrotvrdoće slojeva metodama HV0.3, čvrstoče spoja zatezanjem i mikrostrukture optičkom mikroskopijom (OM) i skening elektronskom mikroskopijom (SEM) su potvrdila da se sa kontrolom plazma struje mogu deponovati slojevi sistema prevlake Al2O328tež.%MgO dobrih mehaničkih i mikrostrukturih karakteristika pogodnih za primenu u eksploataciji za proizvodnju implanata.

Keywords: atmosferski plazma sprej (APS), mikrostruktura, Al2O328tež.%MgO, mikrotvrdoća, čvrstoća spoja.

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Characterization of plasma spray bioinert coating Al2O328wt.%MgO

Abstract

This paper presents the results of testing mechanical and structural characteristics of plasma spray coating Al2O328wt.%MgO. Metal oxide MgO in a complex oxide Al2O328wt.%MgO modifies the properties of Al2O3 ceramics by forming spinel MgAl2O4 with excellent biomedical characteristics. The coating layers were deposited by atmospheric plasma spraying process (APS) on steel substrates of stainless steel X15Cr13 (EN 1.4024). The aim of this study was to examine the effect of the strength of the plasma current (700A, 800A and 900A) on the mechanical properties of the Al2O3MgO coating, pore content and microstructure of the layers. Testing microhardness of  the layers using the HV0.3 method, the bond strength using the tensile method and microstructure using optical microscopy (OM) and scanning electron microscopy (SEM) have confirmed that, by controlling the plasma current, layers of the coating system Al2O328wt.%MgO can be deposited with good mechanical and microstructural characteristics suitable for use in manufacture of implants.

Keywords: atmospheric plasma spray (APS), microstructure, Al2O328wt.%MgO, microhardness, bond strength.

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Xhaklina Cani1*, Ilirjan Malollari1, Lorina Liçi2

1University of Tirana, Faculty of Natural Science, Chemical Process Engineering Group, Department of Industrial Chemistry, Tirana, Albania, 2University of Polytechnic, Geology Faculty,Tirana,  Albania

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:621.1.016.7.001.57
doi: 10.5937/zasmat1901050C


Zastita Materijala 60 (1)
50 – 57  (2019)

Solving simple problems of thermal power plants using simulation techniques

Abstract

A steam/thermal power station uses heat energy generated from burning coal to produce electrical energy. Because of the huge amounts of fuel (coal), this kind of power station can be used to produce large amounts of electrical energy. Wide range of commercial heat and mass balance simulation, analysis and optimization software packages are available on the market. In this paper is presented the use of IPSEpro from SimTech Simulation Technology. The so called software IPSEpro is an exploiting engineering system for calculating heat and mass balances and simulating processes, as well. In the study are presented some simple problems of thermal power plants to calculate mass and energy balances using the simulation program. With this program it was for us possible to analyze the performance of a standard plant as well as the investigation of the influence of particular components on the whole system. Therefore, the constructive design of particular power plant components can be implemented or improved based on the results of the simulations being performed. Our paper is presenting some real simple problem solution using the above mentioned simulation procedure, and we have calculated process conditions through mass and energy balances. Also we have shown the graphical presentation of the most important parameters governing the process for different units of the entire plant.

Keywords: IPSEpro, thermal power plants, simulation.

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Rešavanje jednostavnih problema termoelektrane korišćenjem simulacione tehnike

Izvod

Para/termoelektrana koristi toplotnu energiju proizvedenu iz sagorevanja uglja za proizvodnju električne energije. Zbog obilja goriva (uglja), ova vrsta elektrane se može koristiti za proizvodnju velikih količina električne energije. Širok spektar komercijalnih simulacija balansa toplote i mase, analiza i optimizacija softverskih paketa su dostupni na tržištu. U ovom radu prikazana je upotreba IPSEpro-a iz SimTech Simulation tehnologije. Takozvani softver IPSEpro je eksploatacioni inženjerski sistem za izračunavanje toplotnih i masenih balansa i simulacija procesa. U radu su prikazani pojedini jednostavni problemi termoelektrana za proračun masenih i energetskih bilansa pomoću simulacionog programa. Ovim programom  bilo je moguće analizirati performanse standardnog postrojenja kao i ispitivanje uticaja pojedinih komponenti na celi sistem. Stoga se konstruktivni dizajn pojedinih komponenti elektrane može implementirati ili poboljšati na osnovu rezultata izvršenih simulacija. Ovaj rad predstavlja jedno stvarno jednostavno rešenje problema koristeći gore pomenutu simulacionu proceduru i izračunati su procesni uslovi kroz bilanse mase i energije. Takođe,  grafički su prikazi najvažniji parametari koji regulišu proces za različite jedinice celog postrojenja.

Ključne reči: IPSEpro, termoelektrane, simulacija.

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Mlađan Popović1*, Jasmina Popović1, Milanka Điporovic-Momčilović1, Nevena Vukić2, Jaroslava Budinski-Simendić2, Ivana Gavrilović-Grmuša1, Fadhil Hamid1

1University of Belgrade, Faculty of Forestry, Belgrade, Serbia, 2University of Novi Sad, Faculty of Technology, Novi Sad, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:662.613.11/,13:504.054
doi:10.5937/zasmat1901064P


Zastita Materijala 60 (1)
64 – 69  (2019)

The curing behavior of urea-formaldehyde adhesive in the presence of chemicaly treated narrow-leaved ash

Abstract

The influence of Narrow Leaved Ash (Fraxinus angustifolia Vahl. ssp. Pannonica Soo & Simon) pre-treatments on the curing behavior of urea-formaldehyde (UF) adhesive was studied. Differential scanning calorimetry (DSC) was used to monitor the curing reaction of UF adhesive mixed with non-treated wood flour (control series) and wood flour of Narrow leaved Ash obtained after different pre-treatments of wood particles. Three different pre-treatments were applied, one with sodium carbonate solution (0.03 g/g of dry wood), one with acetic acid solution (0.06 g/g of dry wood) and one with distilled water. The curing reaction of different adhesive systems showed no apparent differences in peak temperature values, and there were no significant differences in the enthalpy of the reaction. However, it was assessed that the activation energy has lower values for the UF systems with alkaline and acid treated wood flour (76.64 and 76.92 kJ/mol) in regard to the UF systems with control (untreated) wood flour and water treated wood flour (79.28 and 79.14 kJ/mol). In addition, the application of iso-conversional models have shown different curing behavior of UF adhesive systems.

Keywords: chemical treatment, narrow-leaved ash, curing kinetics, UF adhesive.

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Očvršćavanje urea-formaldehidnog adheziva u prisustvu hemijski tretiranog drveta poljskog jasena

Izvod

U ovom radu istraživan je uticaj pred-tretmana poljskog jasena (Fraxinus angustifolia Vahl. ssp. Pannonica Soo & Simon) na tok očvršćavanja urea-formaldehidnog (UF) adheziva. Metoda diferecijalne skenirajuće kalorimetrije (DSC) korišćena je za praćenje reakcije očvršćavanja UF adheziva u smeši sa netretiranim drvnim brašnom (kontrolna serija) i drvnim brašnom dobijenim od različito tretiranog iverja poljskog jasena. Primenjena su tri različita pred-tretmana: tretman rastvorom natrijum karbonata (0,03 g/g apsolutno suvog drveta), tretman rastvorom sirćetne kiseline (0,06 g/g apsolutno suvog drveta) i tretman destilovanom vodom. Rezultati praćenja očvršćavanja različitih adhezivnih sistema nisu ukazali na značajne razlike u temperaturama maksimuma reakcije, kao niti u vrednostima entalpije reakcije. Međutim, relativno niže vrednosti energije aktivacije uočene su kod UF adhezivnih sistema sa drvnim brašnom dobijenim nakon alkalnog i kiselog tretmana (76,64 and 76,92 kJ/mol) u odnosu na UF adhezive sa kontrolnim (netretiranim) drvnim brašnom i drvnim brašnom tretiranim vodom (79,28 and 79,14 kJ/mol). Pored toga, primenjene izo-konverzione metode pokazale su različito ponašanje ispitivanih UF adhezivnih sistema tokom očvršćavanja.

Ključne reči: hemijski tretman, poljski jasen, kinetika očvršćavanja, UF adheziv.

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Jelena M. Avramović1, Dragana B. Radosavljević2, Ana V. Veličković1, Ivan J. Stojković3, Olivera S. Stamenković1, Vlada B. Veljković1*

1University of Niš, Faculty of Technology, Leskovac, Serbia, 2University of Priština, Faculty of Technical Sciences, Kosovska Mitrovica, Serbia, 3University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:665.75.001.572
doi:10.5937/zasmat1901070A


Zastita Materijala 60 (1)
70 – 80  (2019)

Statistical modeling and optimization of ultrasound-assisted biodiesel production using various experimental designs

Abstract

The present study compares the performances of the regression models developed by the response surface methodology combined with the full factorial, Box-Behnken or face central composite designs applied for the ultrasound-assisted KOH–catalyzed methanolysis of sunflower oil. While all models led to similar optimal reaction conditions, the models based on the simpler designs had the smaller corrected Akaike information criterion values, the insignificant lack of fit and the more favorable statistical criteria than the model based on the full factorial design. Including fewer experiments, the Box-Behnken design can be recommended for the optimization of ultrasound-assisted biodiesel production processes.

Keywords: biodiesel, Box-Behnken design, face central composite design, full factorial design, response surface methodology, ultrasound-assisted transesterification.

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Statističko modelovanje i optimizacija proizvodnje biodizela u prisustvu ultrazvuka primenom različitih eksperimentalnih planova

Izvod

U radu se porede performanse regresionih modela razvijenih na osnovu kombinovanja metodologije površine odziva sa punim faktorijelnim, Boks-Benken-ovim ili centralnim kompozitnim planom kada se primene na ultrazvukom podržanu bazno-katalizovanu metanolizu suncokretovog ulja. Iako su svi modeli dali slične optimalne uslove reakcije, modeli zasnovani na jednostavnijim planovima imali su manje vrednosti Akaike-ovog informacionog kriterijuma, neznačajnu vrednost odstupanja od modela i povoljnije statističke kriterijume u odnosu na model zasnovan na punom faktorijelnim planu. Boks-Benken-ov plan, koji zahteva manji broj eksperimenata, može da se preporuči za optimizaciju proizvodnje biodizela u ultrazvučnom reaktoru.

Ključne reči: Biodizel, Boks-Benken-ov plan, centralni kompozitni plan, pun faktorijelni plan, metodologija površine odziva, ultazvučna transesterifikacija.

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Milena D. Milošević1, Dunja D. Daničić2, Jovanka N. Kovačina2, Mladen D. Bugarčić3, Jelena D. Rusmirović4, Tihomir M. Kovačević4, Aleksandar D. Marinković5*

1University of Belgrade, Institute of Chemistry, Technology and Metallurgy, National Institute, Department of Ecology and Techoeconomic, Belgrade, Serbia,2University of Belgrade, Institute of Chemistry, Technology and Metallurgy, National Institute, Department of Electrochemistry, Belgrade, Serbia,3Institute for Technology of Nuclear and Other Mineral Raw Materials, Belgrade, Serbia, 4Military Technical Institute, Belgrade, Serbia

5University of Belgrade, Faculty of Technology and Metallurgy, Department of Organic Chemistry, Belgrade, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:620.197.60
doi:10.5937/zasmat1901081M


Zastita Materijala 60 (1)
81 – 95  (2019)

Modified tannins for alkyd based anticorrosive coatings

Abstract

The study of the synthesis of anticorrosive inhibitors, based on chemically modified tannins, and their use in alkyd based coatings to improve anticorrosive properties is presented in this work. Two methods of tannin modification were applied: direct method using ammonium hydroxide, ammonium hydroxide/ammonium chloride buffer or diethylenetriamine (DETA); and a two-step method including tannin modification with epichlorohydrin (ECH) in first step to produce epoxy modified tannin, ET, and further modification with heteroaromatic amines or linseed oil fatty acids (LFA) in second step. The obtained anticorrosive additives were characterized using ATR-FTIR, 1H and 13C NMR spectroscopies and elemental analysis. Epoxy, amino, hydroxyl, acid and iodine values of the synthesized inhibitors were determined according to standard methods. The prepared alkyd coating with tannin inhibitors was tested according to standard SRPS EN ISO 4628 method. Anticorrosive coating containing modified tannin based additive showed increased anticorrosive properties, good adhesion and coverage comparing to the coating with zinc phosphate additive. The alkyd coating films based on ET-LFA and ET modified with 2-amino-5-mercapto-1,3,4-thiadiazole showed best anticorrosive results.

Keywords: modified tannin, anticorrosion additive, corrosion, alkyd coating.

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Primena modifikovanih tanina u antikorozionim alkidnim premazima

Izvod

U ovom radu prikazana je sinteza antikorozionih aditiva na bazi hemijski modifikovanog tanina i njihova primena u alkidnim premazima u cilju poboljšanja antikorozionih svojstava. Prikazane su dve metode modifikacije tanina: direktna modifikacija tanina primenom amonijum-hidroksida, amonijum-hidroksid/amonijum-hlorid pufera ili dietilentriamina (DETA); i dvostepena modifikacija tanina koja u prvom stupnju uključuje modifikaciju epihlorhidrinom sa ciljem da se dobije tannin sa epoksi terminiranim funkcionalnim grupama, ET, i modifikaciju ET tanina sa heteroaromatičnim aminima ili masnim kiselinama izolovanim iz lanenog ulja (LFA) u drugom stupnju. Sintetisani antikorozioni aditivi su okarakterisani primenom ATR-FTIR, 1H i 13C NMR spektroskopija, i elementalnom analizom. Sadržaj epoksi, amino, hidroksilnih i karboksilnih grupa i vrednost jodnog broja sintetisanih aditiva određen je prema standardnim metodama. Alkidni premazi koji sadrže antikorozione aditive na bazi modifikovanog tanina ispitani su prema standardnoj SRPS EN ISO 4628 metodi. Antikorozivni alkidni premazi na bazi modfikovanih tanina pokazali su poboljšane antikorozione karakteristike i adheziju u poređenju sa alkidnim premazom na bazi cink-fosfata. Alkidni premazi koji sadrže dvostepeno modifikovani tanin sa LFA i 2-amino-5-merkapto-1,3,4-tiadiazolom pokazali su najbolje antikorozione karakteristike.

Ključne reči: modifikovani tanini, antikorozioni aditivi, korozija, alkidni premazi

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Ana Vujošević1, Srdjan Matijašević2*, Sonja Smiljanić3, Jelena Nikolić2, Bogoljub Zečević4, Vladimir Topalović2, Veljko Savić2

1University of Belgrade, Faculty of Agriculture, Zemun, Serbia, 2Institute for Technology of Nuclear and Other Mineral Raw Materials (ITNMS), Belgrade, Serbia, 3University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia, 4Institute for Vegetable Crops, Smederevska Palanka, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:631.461.7
doi:10.5937/zasmat1901096V


Zastita Materijala 60 (1)
96 – 104  (2019)

Polyphosphate glass as fertilizer for plant seedlings

Abstract

Due to the dissolution properties the phosphate glasses can be promising materials for the development of new ecologically safe fertilizers. The complex polyphosphate glass with a molar ratio (M2O + MO)/P2O5 >1 and addition of microelements Zn2+, Mn2+, Fe3+ and Cu2+ were used in substrate for production of flower and vegetables seedlings. Dissolution tests were conducted in deionized water and 2% citric acid. The effects of the reaction time on the normalized glass mass loss (fm) and the normalized concentrations of the ions (fi) at 20, 30, 37 and 50°C were determined. Dissolution rate constants (kw – deionized water, kc -2% citric acid) were also determined (kw-0.0028-0.0094 gm-2, kc-0.029-0.011 gm-2). Values of kc were higher than those of kw, which confirms a significant effect of solvent type and temperature on the dissolution kinetics of glass. The experiments with plants (one vegetable and one flower) showed that the addition of phosphate glass caused an increase in yield and quality of plants. The applied dose of polyphosphate glass of 1gl-1 showed the best effect on the growth of the examined plant seedlings.

Keywords: polyphosphate glass, substrata, plant, seedlings.

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Efekat primene polifosfatnog stakla u supstratima za gajenje cveća i povrća  

Izvod

Polifosfatno staklo, u kome je molski odnos (M2O + MO)/P2O5 >1, koje sadrži i mikroelemente Zn2+, Mn2+, Fe3+ i Cu2+, korišćeno je u supstratu za proizvodnju rasada cveća i povrća. Eksperimenti su izvedeni u stakleniku na Poljoprivrednom fakultetu u Beogradu i u laboratorijama ITNMS. Ispitivano je ponašanje polifosfatnog stakla prilikom rastvaranja u dejonizovanoj vodi i 2% rastvoru limunske kiseline na temperaturama od 20, 30, 37 i 50 °C. Ispitan je uticaj vremena rastvaranja na normalizovani gubitak mase (fm) i normalizovane koncentracije jona (fi). Određene su i konstante brzina rastvaranja(kw-dejonizovana voda, kc -2% rastvor limunske kiseline). Vrednosti kc su veće od vrednosti za kw, što potvrđuje uticaj rastvarača i temperature na proces rastvaranja. Rezultati su pokazali pozitivan efekat polifosfatnog stakla na rast i kvalitet ispitivanih biljaka. Primenjena doza polifosfatnog stakla od 1 gl-1 pokazala je najbolji efekat na rast ispitivanih biljaka-rasada

Ključne reči: polifosfatno staklo, supstrat, biljka, rasad.

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Jelena V. Petrović1, Slađana Č. Alagić2*, Snežana B. Tošić3, Mirjana M. Šteharnik1, Mile M. Bugarin1, Zoran O. Stevanović1

1Institut za rudarstvo i metalurgiju u Boru, Bor, Srbija, 2Univerzitet u Beogradu, Tehnički fakultet Bor, Bor, Srbija,

3Univerzitet u Nišu, Prirodno-matematički fakultet, Niš, Srbija

Short Communication
ISSN 0351-9465, E-ISSN 2466-2585
UDC:631.427.3:504.75.064
doi:10.5937/zasmat1901105P


Zastita Materijala 60 (1)
105 – 111  (2019)

Sadržaj teških metala u nadzemnim delovima koprive i mlečike iz Oštrelja (opština Bor): prilog ispitivanjima biljnih biomonitoring i fitoremedijacionih potencijala

Izvod

U ovom radu, ispitivan je sadržaj teških metala: Cu, Cd, Zn, Ni, Pb i As u nadzemnim delovima koprive i mlečike sa područja seoskog naselja Oštrelj (4-5 km udaljeno od rudarsko-topioničarskog kompleksa u Boru, Srbija), u cilju preliminarne procene njihovih biomonitoring i fitoremedijacionih potencijala. Najobilniji detektovani metal kod obe biljne vrste bio je Cu, uz napomenu da su njegove koncentracije čak dostizale fitotoksične nivoe. Slično je bilo nađeno i u slučaju As i Ni kod mlečike koja se generalno pokazala mnogo efikasnijom u akumulaciji metala u odnosu na koprivu. Kako su se obe ispitivane biljke pokazale kao tolerantne prema određenim metalima (odražavajući istovremeno i postojanje kontaminiranosti u tim slučajevima), može se zaključiti da je njihova primena u biomonitoringu zagađenih oblasti moguća, dok, kada je u pitanju primena u fitoekstrakciji (kao jednoj od najefektnijih fitoremedijacioih metoda), može se reći da je jedino mlečika pokazala izvestan potencijal u ovom pogledu i to naročito u slučaju Cu.

Ključne reči: biomonitoring; fitoekstrakcija; kopriva; mlečika; teški metali.

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The content of heavy of metals in the aerial parts of the common nettle and sun spurge from Oštrelj ( municipality of Bor):  a contribution to the examinations of plant biomonitoring and phytoremediation potentials

Abstract

In this paper, the content of heavy metals Cu, Cd, Zn, Ni, Pb, and As in the aerial parts of the common nettle and sun spurge from the territory of rural settlement Oštrelj (4-5 km far from the mining metallurgical complex in Bor, Serbia) was investigated in terms of preliminary estimation of their biomonitoring and phytoremediation potentials. The most abundant detected metal in both plant species was Cu, with the notification that its concentrations reached even phytotoxic levels. Similar situation was found also in the case of As, and Ni in the sun spurge, which showed to be much efficient in metal accumulation than common nettle. Since both investigated plants showed as tolerant species regarding certain metals (reflecting at the same time the existence of contamination in these cases), it can be concluded that their application in biomonitoring of polluted areas is possible, whereas, when the application in phytoextraction (as one of the most effective phytoremediation methods) is the matter of interest, it can be said that only sun spurge showed some potential in this regard, especially in the case of Cu.

Keywords: biomonitoring; phytoextraction; common nettle; sun spurge; heavy metals

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