Zaštita materijala 3. 2019

 

On the synthesis of 3-cyano-6-hydroxy-4-methyl-2-pyridone at room temperature

Abstract

Milling of cyanoacetamide and acetoacetic ester as reactants, in the presence of KOH as the catalyst and ethanol as a viscous control agent (VCA) was performed in a planetary ball mill with the goal of investigating the effect of mechanochemical treatment for the synthesis of 3-cyano-6-hydroxy-4-methyl-2-pyridone at room temperature. The mechanochemical synthesis was performed under various milling parameters, i.e. milling time up to 4 h, number and size of balls, angular velocity as well as molar ratio of reactants and the amount of catalyst. The obtained product was characterized by m.p., UV, IR and NMR data. It was fond that the dominant process parameter is the milling time while others are of less importance. The highest isolated yield after milling was up to 56%. The combination of milling and aging increase yield over 60%.

Keywords: cyanoacetamide, acetoacetic ester, mechanochemical synthesis, planetary ball mill, optimization.

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O sintezi 3-cijano-6-hidroksi-4-metil-2-piridona na sobnoj temperaturi

Izvod

Mlevenje cijanoacetoamida (2) i acetsirćetnog estra (1) kao reaktanata, u prisustvu KOH kao katalizatora i etanola kao agensa kojim se kontroliše viskoznost, izvedeno je u planetarnom mlinu radi ispitivanja mogućnosti mehanohemijske sinteze 3-cijano-6-hidroksi-4-metil-2-piridona (3) na sobnoj temperaturi. Mehanohemijski tretman je izveden sa različitim parametrima mlevenja: vremenom mlevenja do 4 h, različitom veličinom i brojem kuglica, različitom brzinom obrtanja, kao i različitim molarnim odnosom reaktanata i katalizatora. Dobijeni proizvod je okarakterisan određivanjem temperature topljenja, UV, IR i NMR analizama. Nađeno je da je dominantni procesni parametar vreme mlevenja, dok su ostali od manjeg uticaja. Najveći prinos izolovanog proizvoda je oko 56%, dok se naknadnim „odležavanjem“ prinos povećava preko 60%.

Ključne reči: cijanoacetamid, acetsirćetni estar, mehanohemijska sinteza, planetarni mlin sa kuglama, optimizacija.

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Toksičnost osnovnih komponenti u Li-jonskim baterijama

Izvod

Li-jonske baterije sadrže veliki broj štetnih komponenti, čije prisustvo u životnoj sredini može izazvati neželjene posledice po zdravlje ljudi. Primenom inovacija u tehnologiji reciklaže Li-jonskih baterija može se postići značajan stepen zaštite ljudi i životne sredine uopšte. Međutim, opasnost od ekspolozije i oslobađanja toksičnih materija ne može biti isključena čak ni u slučaju primene najnovijih modernih tehnologija. U cilju blagovremenog prepoznavanja potencijalnih opasnosti, u ovom radu je opisano moguće toksikološko dejstvo najvažnijih komponenti Li-jonskih baterija, sa posebnim akcentom na upotrebljene elektrolite. Takođe, predložene su i određene mere predostrožnosti prilikom reciklažnih postupaka, a koje bi u znatnoj meri poboljšale bezbednost uposlenih lica.

Ključne reči: Li-jonske baterije, reciklaža, toksičnost.

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Toxicity of basic componenents in Li-ION batteries 

Abstract

Lithium-ion batteries are constituted of many harmful components; the presence of these components in the environment may negatively affect human health. The application of innovations in Li-ion batteries recycling technologies, contributes to the protection of humans and the complete environment in a significant degree. However, the hazard from explosions or toxic matter emissions cannot be excluded even in the case of the application of modern technologies. In terms of recognizing the potential hazards, this paper describes possible toxic effects of the most important components of Li-ion batteries, with special accent on used electrolytes. Also, in terms of improving the employee’s safety, this paper suggests certain protective measures during the recycling procedures.

Keywords: Li-ion batteries, recycling, toxicity.

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Esomeprazole Magnesium Trihydrate drug as a potential non-toxic corrosion inhibitor for mild steel in acidic media

Abstract 

The inhibiting effect of Esomeprazole Magnesium Trihydrate drug on the corrosion of mild steel (MS) in 1 M HCl was performed by chemical tests (weight loss (WL)) and electrochemical methods (Tafel polarization (TP), electrochemical frequency modulation (EFM) and AC impedance spectroscopy (EIS)). The adsorption isotherm of Esomeprazole Magnesium Trihydrate drug on the MS surface was found to follow Temkin adsorption isotherm. Some thermodynamic parameters were computed and discussed. The obtained data showed that the inhibition efficiency (IE) rises with increasing the dose of the Esomeprazole Magnesium Trihydrate and with raising the temperature. The morphology of MS surface was analyzed by using scanning electron microscope (SEM), atomic force microscopy (AFM), and Fourier transforms infrared spectroscopy (FTIR) techniques. All test methods were in good agreement with each other.

Keywords: Acid corrosion, Mild steel, SEM, AFM, FTIR, Esomeprazole Magnesium trihydrate.

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Lek Esomeprazole Magnesium Trihydrate kao potencijalni neotrovni inhibitor korozije za meki čelik u kiselim medijima

Izvod

Inhibitorski efekat leka Esomeprazole Magnesium Trihydrate  na koroziju mekog čelika (MS) u 1M HCl ispitan je hemijskim testovima (gubitak težine (VL)) i elektrohemijskim metodama (Tafelova polarizacija (TP), elektrohemijska frekventna modulacija (EFM) i AC impedansna spektroskopija (EIS)). Otkriveno je da je adsorpciona izoterma leka Esomeprazole Magnesium Trihydrate na površini MS praćena Temkinovom adsorpcionom izotermom. Neki termodinamički parametri su izračunati i diskutovani. Dobiveni podaci pokazali su da se efikasnost inhibicije (IE) povećava s povećanjem koncentracije Esomeprazole Magnesium Trihydrate i povećanjem temperature. Morfologija MS površine analizirana je korišćenjem skenirajućeg elektronskog mikroskopa (SEM), atomske mikroskopije (AFM) i FTIR tehnikom. Rezultati svih metoda ispitivanja bili su u međusobnom slaganju.

Ključne reči: kisela korozija, meki čelik, SEM, AFM, FTIR, Esomeprazole Magnesium Trihydrate.

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Corrosion problems in electronic systems

Abstract

Microelectronics and, chiefly, silicon integrated circuit microelectronics, has created astonishing capabilities over the last 40 years. Speedy advancement in CMOS transistor equipment leading to the gigahertz speeds common today has necessitated chief changes in semiconductor manufacturing technology and the expansion of high frequency compatible packaging. The progress of an optimized formulation for electroless nickel (EN) plating with a long life span to make a deposit with good corrosion resistance (CR). The electroless deposition of Ni-P alloys is widely used in diverse fields such as aerospace, automation, electronics, nuclear, oil and gas production, and valve industries. Lead frame is the primary package metallurgical bond pad interface in microelectronic devices which provides external interconnection. The most predominant lead frame material is copper with tin plating. Over the years, galvanic corrosion and copper oxidation are two major reliability concerns for any microelectronics packages with copper lead frame, when operating under high humidity environment.

Keywords: electronics, corrosion, bimetallic corrosion, electronic components, silver bonding.

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Problemi korozije u elektronskim sistemima

Izvod

Mikroelektronika i, uglavnom, silikonska mikroelektronika sa integrisanim krugom stvorili su zadivljujuće sposobnosti u poslednjih 40 godina. Brzo napredovanje u CMOS tranzistorskoj opremi, što dovodi do brzina gigaherca uobičajenih danas, zahteva velike promene u tehnologiji proizvodnje poluvodiča i širenje ambalaže kompatibilne sa visokom frekvencijom. Napredak optimizovane formulacije za oblaganje nikleom (EN) bez elektronike sa dugim vekom trajanja za deponovanje sa dobrom otpornošću na koroziju (CR). Elektro-taloženje legura Ni-P široko se koristi u raznim oblastima kao što su vazduhoplovstvo, automatizacija, elektronika, nuklearna, proizvodnja nafte i gasa i industrija ventila. Olovni okvir je primarni metalurški interfejs paketa u mikroelektronskim uređajima koji omogućava spoljnu povezanost. Najviše preovlađujući materijal od olovnog okvira je bakar sa limenom oblogom. Tokom godina, galvanska korozija i oksidacija bakra dve su glavne brige o pouzdanosti za bilo koji paket mikroelektronike sa bakarnim olovnim okvirom, kada rade u okruženju sa visokom vlagom.

Ključne reči: elektronika, korozija, bimetalna korozija, elektronske komponente, vezivanje srebra.

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Mehanička svojstva i mikrostruktura slojeva prevlake molibdena deponovane vakuum plazma sprej procesom

Izvod

Prevlake molibdena se zbog svojih odličnih osobina na habanje i kliznih svojstva u uslovima suvog trenja često koriste u aplikacijama da se odupru trenju i suvom klizanju. Pošto je molibden metal osetljiv na oksidaciju, u ovoj studiji slojevi prevlake molibdena su uspešno deponovani na niskom pritisku inertnog gasa Ar vacuum plazma sprej tehnologijom (VPS). Karakterizacija prevlake Mo je izvršena merenjem mikrotvrdoće slojeva prevlake metodom Vickers HV_0.3, čvrstoće spoja ispitivanjem na zatezanje i mikrostrukture metodom optičke mikroskopije (OM) i skening elektronske mikroskopije (SEM). Mikrostruktura slojeva prevlake je ispitana u deponovanom stanju i posle nagrizanja. Za nagrizanje se koristio reagens NH₃·H₂O i H₂O₂ sa zapreminskim odnosom 1:2. Dobijeni rezultati su pokazali da prevlaka ima dobre mehaničke karakteristike, mikrotvrdoću i visoku adheziono / kohezionu čvrstoću. Slojevi VPS – Mo prevlake su se sastojali od dobro istopljenih čestica praha, delimično neistopljenih čestica sa dobrom vezom u slojevima prevlake i mikro pora sa udelom ispod 0,5%. Utvrđeno je da se mikrostruktura prevlake uglavnom sastoji od lamelarne strukture i stubastih kristalnih zrna Mo. Ispitivanja su pokazala da VPS – Mo slojevi prevlake imaju mehaničke karakteristike i mikrostrukturu koje u potpunosti omogućavaju primenu prevlake na površinama delova od kojih se zahteva da imaju dobra klizna svojstva, otpornost na habanje i koroziju.

Ključne reči: Molibden, vakuum plazma sprej (VPS), mikrostruktura, mikrotvrdoća, čvrstoća spoja

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Mechanical properties and microstructure of molybdenum coating layers deposited vacuum plasma spray process

Abstract

Molybdenum coatings due to their excellent wear resistant properties and sliding characteristics under dry friction conditions are often used in applications to resist friction and dry sliding. Since molybdenum metal is susceptible to oxidation, in this study, the molybdenum coating layers were successfully deposited at low pressure inert gas Ar using vacuum plasma spray technology (VPS). Characterization of the Mo coating was performed by measuring the microhardness of the coating layers using the Vickers HV_0.3 method, the bond strength by tensile testing and the microstructure by optical microscopy (OM) and scanning electron microscopy (SEM). The microstructure of the coating layers was tested in deposited stateand after etching. The etching reagent used was NH₃·H₂O and H₂O₂ with a volume ratio of 1:2. The results showed that the coating has good mechanical properties, microhardness and high adhesion/cohesion strength. Layers of VPS – Mo coatings were composed of well-melted powder particles, partially unmelted particles with a good bond in the coating layers and micropores with a share below 0.5%. It was found that the microstructure of the coating consists mainly of lamellar structure and columnar crystal Mo grains. Tests have shown that the VPS – Mo coating layers have mechanical characteristics and a microstructure which fully enables the use of the coating on surfaces of parts which are required to have good sliding properties, resistance to wear and corrosion.

Keywords: Molybdenum, vacuum plasma spray (VPS), microstructure, microhardness, bond strength.

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Ispitivanje korozije ugljičnog čelika P235 u deioniziranoj vodi

Izvod

U radu je ispitano korozijsko ponašanje čelika P235 koji se koristi za izradu cijevi u pogonu za mekšanje vode ionskim izmjenjivačima. Ispitivanja su provedena u deioniziranoj vodi bez i uz dodatak komercijalnog biocida i inhibitora korozije, metodom mjerenja gubitka mase te elektrokemijskim metodama (metodom linearne i potenciodinamičke polarizacije). Nakon potenciodinamičkog polarizacijskog ispitivanja površina čelika ispitana je optičkim mikroskopom.

Ustanovljeno je da u deioniziranoj vodi dolazi do opće korozije čelika. Dodatak komercijalnog biocida (Chemtec BI01) ne mijenja korozijsko ponašanje čelika, dok primijenjeni komercijalni inhibitor (Chemtec FI30) smanjuje brzinu korozije čelika u deioniziranoj vodi na prihvatljivu vrijednost djelujući kao anodni tip inhibitora.

Međutim, anodna polarizacija na uzorku čelika u deioniziranoj vodi izazva pojavu jamičaste korozije, a oštećenja površine su znatno manja u inhibiranim otopinama.

Ključne reči: ugljični čelik, korozija, polarizacija, optička mikroskopija.

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Corrosion investigations of P235 carbon steel in deionized water

Abstract

In this paper results of the corrosion behavior of steel P235 used for pipes in the water softening plant with ion exchangers were reported. Investigations were carried out in deionized water without and with the addition of commercial biocides and corrosion inhibitors, using mass loss measurement method and electrochemical methods (linear and potentiodynamic polarization method). After potentiodynamic polarization investigations, the surface of the steel was examined by optical microscopy. It has been found that general corrosion of steel occurs in deionized water. The addition of the commercial biocide (Chemtec BI01) does not alter the corrosion behavior of the steel while application of commercial inhibitor (Chemtec FI30) reduces the corrosion rate of the steel in deionized water to an acceptable value acting as an anodic type of corrosion inhibitor. However, anodic polarization on steel sample in deionized water causes the appearance of pitting corrosion, and surface damage is considerably lower in inhibited solutions.

Keywords: carbon steel, corrosion, polarization, optical microscopy.

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Korozija i zaštita betona u pogonu za proizvodnju katodnog bakra

Izvod

Najkompleksniji vid korozije u pogonima Topionice i rafinacije bakra u Boru prisutan je u pogonu Elektrolitičke rafinacije bakra, gde rastvor bakar(II)-sulfata izaziva koroziju betona i betonske armature kao i primenjenih čeličnih materijala. Posebno su  izraženi  procesi korozije i destrukcije betonskih površina. Korozija betonske armature prepoznaje se kao glavni uzrok degradacije betonske strukture u mnogim slučajevima, kako pod uticajem sulfata, tako i pod uticajem hloridnih jona. U tom pogledu i sistem zaštite zahteva poznavanje korozione problematike, kako čeličnih, tako i betonskih površina. Sistem zaštite koji se primenjuje u pogonima elektrolize bakra sastoji se od polaganja kiselootpornih pločica u epoksidnu masu, na prethodno prajmerisanu betonsku podlogu. Ovakav sistem zaštite pruža trajnost zaštite od minimum 10 godina.

U ovom radu su prezentovani problemi korozije betonskih konstrukcija koji se svakodnevno javljaju u pogonima Elektrolitičke rafinacije bakra u Boru i metode zaštite od korozije.

Ključne reči: elektrolitička rafinacija bakra, beton, korozija, zaštita, epoksidne mase.

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Corrosion and corrosion protection of concrete in the cathode copper  production plant

Abstract

The most complex type of corrosion in the plants of Copper Smelter and Refineries in Bor is present in the plant of Electrolytic Copper Refinery, where the solution of copper (II) sulfate causes the corrosion of concrete and concrete reinforcement as well as the applied steel materials. The processes of corrosion and destruction of concrete surfaces are particularly pronounced. Corrosion of concrete reinforcement is recognized as the main cause of degradation the concrete structure in many cases, both under the influence of sulfates and the influence of chloride ions. Regarding to this, the protection system also requires a knowledge on corrosion problems, both steel and concrete surfaces. The protection system applied in the Copper Electrolysis Plants consists of laying the acid-resistant plates in the epoxy mass, on a previously primed concrete base. This protection system provides minimum 10 years of a protection durability.

This work will present the problems of corrosion of concrete structures that occur daily in the plants of Copper Electrolytic Refinery in Bor, the method they are solved and the method of applying the protection systems.

Keywords: electrolytic refining of copper, concrete, corrosion protection, epoxy mortar.

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Identification of lead concentration in soil samples

Abstract

Lead is widely used in industry for building construction, lead-acid batteries, bullets, shot, etc. Lead poisoning is an important environmental pollutant that can have life-long adverse health effects. Lead causes symptoms ranging from the loss of neurological function to death depending upon the extent and duration of exposure. The current study reports the determination of lead concentration in soil samples, distribution of lead on the surface and its penetration in the profile of soils. For this purpose 21 sampling points at a distance 80-600 m around Former Factory Production of Batteries to Berat, Albania were selected. Soil samples (surface and profile) were collected, and were analyzed using Atomic Absorption Spectrometry for their lead content. The concentration ranges of lead in soil samples collected at different points are compared with the Maximum Contaminant Levels (MCL) specified by the Directive 86/278/EEC. From results obtained the fraction of lead in surface soil samples were in range: 126 mg/kg-24207 mg/kg. Hazardous Quoted (HQ) for each point sampling was calculated. The level of lead in the profile of worked soil samples, in the depth 20-30 cm has decreased compared to the concentration of lead concentration in surface soil samples.

Keywords: lead, surface and profile soil samples, Atomic Absorption Spectrometry (AAS).

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Identifikacija koncentracije olova u uzorcima tla

Izvod

Olovo se široko koristi u industriji za izgradnju građevina, baterija sa olovnim pločama, metaka, itd. Olovo je važan zagađivač životne sredine, koji može imati štetne štetne posledice po život. Olovo izaziva simptome u rasponu od gubitka neurološke funkcije do smrti u zavisnosti od obima i trajanja izloženosti. Ova studija izveštava o utvrđivanju koncentracije olova u uzorcima tla, distribuciji olova na površinu i njegovom prodiranju u profil tla.  U tu svrhu je odabrano 21 mesto uzorkovanja na udaljenosti od 80-600 m oko bivše fabrike za proizvodnju baterija u mestu Berata, Albanija. Uzorci tla (površina i profil) su sakupljeni i analizirani pomoću atomske apsorpcione spektrometrije za sadržaj olova. Raspon koncentracija olova u uzorcima tla prikupljenih u različitim tačkama upoređeni su sa maksimalnim nivoima kontaminanata (MCL) navedenim Direktivom 86/278 / EEZ. Iz dobijenih rezultata udio olova u uzorcima površinskog zemljišta bio je u opsegu: 126 mg / kg-24207 mg / kg. Nivo olova u profilu obrađenih uzoraka tla u dubini od 20-30 cm smanjen je u odnosu na koncentraciju olova u površinskim uzorcima tla.

Ključne reči: olovo, površine i profili, atomska apsorpciona spektrometrija (AAS).

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