Vinyl and imino derivatives of pyridine: synthesis, physico-chemical characterization, biological activity, and theoretical studies of electronic structure

Предмет истраживања ове докторске дисертације је синтеза, структурна карактеризација винил и имино деривата пиридина и испитивање њихове потенцијалне биолошке активности. Синтетисане су три серије једињења:1. симетрични 1-метил-2,6-(bis)[2-(супституисани фенил)етенил]пиридинијум-јодиди (bis(винил)пиридинијум-јодиди – БВПЈ)2. симетрични N,N'-(пиридин-2,6-диил)bis[1-(супституисани фенил)]метанимини (bis(имино)пиридини – БИП)3. асиметрични дихидразони тиокарбохидразида (дТКХ)...The main topic of this doctoral dissertation is the synthesis, structural characterization, and examination of potential biological activities of vinyl and imino derivatives of pyridine. Three series of compounds were synthesized:1. Symmetric 1-methyl-2,6-(bis)[2-(substituted phenyl)ethenyl]pyridinium iodide (bis(vinyl) pyridinium-iodide – БВПЈ)2. Symmetric N,N'-(pyridine-2,6-diyl)bis[1-(substituted phenyl)]methanimines (bis(imino)pyridines – БИП)3. asymmetric thiocarbohydrazide dihydrazones (дТКХ)..

Vinyl and imino derivatives of pyridine: synthesis, physico-chemical characterization, biological activity, and theoretical studies of electronic structure

Предмет истраживања ове докторске дисертације је синтеза, структурна карактеризација винил и имино деривата пиридина и испитивање њихове потенцијалне биолошке активности. Синтетисане су три серије једињења: 1. симетрични 1-метил-2,6-(bis)[2-(супституисани фенил)етенил]пиридинијум-јодиди (bis(винил)пиридинијум-јодиди – БВПЈ) 2. симетрични N,N'-(пиридин-2,6-диил)bis[1-(супституисани фенил)]метанимини (bis(имино)пиридини – БИП) 3. асиметрични дихидразони тиокарбохидразида (дТКХ)...The main topic of this doctoral dissertation is the synthesis, structural characterization, and examination of potential biological activities of vinyl and imino derivatives of pyridine. Three series of compounds were synthesized: 1. Symmetric 1-methyl-2,6-(bis)[2-(substituted phenyl)ethenyl]pyridinium iodide (bis(vinyl) pyridinium-iodide – БВПЈ) 2. Symmetric N,N'-(pyridine-2,6-diyl)bis[1-(substituted phenyl)]methanimines (bis(imino)pyridines – БИП) 3. asymmetric thiocarbohydrazide dihydrazones (дТКХ)..

Microwave-Assisted of synthesis and characterizations of levulinic acid (LA)

Levulinic acid (4-oxopentanoic acid) (LA) is a two-functional γ-keto acid widely used in a production of pharmaceuticals, ethyl levulinate, the substance which is widely used in the cream and perfume industry, polymers, plasticizers, biofuel, resins, and various other additives. LA was synthesized by the dehydration of fructose in a strongly acidic aqueous medium, using diluted hydrochloric acid, and subjected to microwave irradiation at different operational conditions. LA was further used in two subsequent steps of peroxidation and dehydration to obtain 3-hydroxypropanoic acid and maleic anhydride (MA) and acrylic acid (AA), respectively, which could be used for acrylic ester synthesis which could be used as a monomer in a polyacrylate production (Figure 1).Poster presented at: 7 th Conference of Young Chemists of Serbia, Belgrad

Primena modifikovanih tanina u antikorozionim alkidnim premazima

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.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

Optimization of Microwave-Assisted synthesis of 5-hydroxymethyl-2-furfural

Heterocyclic furan-based compounds are interesting bio-renewable materials used as intermediate for pharmaceuticals, biodegradable resins, biofuels and fine chemicals syntheses. Additionally, HMF also functions as an anti-sickling agent for intermolecular sickle hemoglobin without inhibition by plasma and tissue proteins or other undesirable sequences.Poster presented at: 7 th Conference of Young Chemists of Serbia, Belgrad

Supplementary material for the article: Rančić, M. P.; Stojiljković, I.; Milošević, M.; Prlainović, N.; Jovanović, M.; Milčić, M. K.; Marinković, A. D. Solvent and Substituent Effect on Intramolecular Charge Transfer in 5-Arylidene-3-Substituted-2,4-Thiazolidinediones: Experimental and Theoretical Study, 2016. https://doi.org/10.1016/j.arabjc.2016.12.013

Supplementary material for: [https://doi.org/10.1016/j.arabjc.2016.12.013]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/305

Mechanical Properties of Composite Material Reinforced With Silica Particles Obtained from Biomass Modified With Double-Layered Hydroxides

Silica particles were produced form rice husk and used as reinforcement in the polymer matrix. The obtained silica particles' surfaces were modified with layered double hydroxides, which enabled better reinforcement in the PMMA matrix. Coprecipitation was used to synthetize Fe Al layered double hydroxides (LDH) with a Fe:Al cation content of 3:1 and an FeAl-LDH: silica ratio of 1:1. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with EDS were used to characterize the synthesized particles. The prepared particle amounts in the PMMA matrix were 1, 3, and 5 wt. %. The purpose of this study was to see if the obtained SiO2 particles, as well as their modification with FeAl-LDH, had any effect on the mechanical properties of polymer composite materials. The mechanical characterization of obtained composites was done using Vickers microindentation tests and impact testing. The Vickers micro-hardness test showed that the addition of reinforcement increases the hardness of the composite. When compared to the matrix, the toughness of the composite material with a higher content of particles (5 wt. %) in the energy absorbed in this impact test was three times higher.The book of abstract available at: [http://conf.univerzitetpim.com/wp-content/uploads/2022/06/Book-of-Abstracts_2022-1.pdf

Purification of waste water using ozonization

Usled razvoja industrije i rastom populacije tokom poslednjih godina javljaju se problemi u vezi sa otpadnim vodama iz proizvodnje koje je neophodno rešavati na ekološki i ekonomičan način. Sve otpadne vode iz postrojenja bez obzira kako su nastale sadrže štetne materije koje mogu da imaju i određen stepen toksičnih primesa, moraju se prečistiti ako njihov kvalitet ne odgovara zakonskim okvirima. Svrha tretmana otpadnih voda je uklanjanje štetnih materija čime se postiže smanjnje stepena njene zagađenosti, a istovremeno se ostvaruje i određen ekonomski i ekološki efekat, stoga je u ovom radu izvršeno prečišćavanje otpadne vode postupkom taloženja upotrebom kalcijum-oksida u cilju uklanjanja koloidnih materija i teških metala. Većina zagađujućih materija su organskog porekla i njihovo ukljanjanje vršiće se primenom naprednih oksidacionih procesa korišćenjem ozona i ozona u kombinaciji sa ultrazvukom u cilju postizanja kvaliteta vode koji odgovara zakonskoj regulativi. Proces prečišćavanja će se optimizovati u odnosu na tehnološki postupak, koncentraciju, vreme tretmana i količinu primenjenog oksidacionog sredstva. Stepen zagađenosti vode organskim jedinjenjima će se određivati na osnovu merenja HPK, BPK i koncentracije teških metala (olovo, gvožđe, hrom, bakar, cink, aluminijum).Due to the development of industry and population growth during the in recent years, there are problems with wastewater from production that needs to be addressed in an environmentally and economical way. All wastewaters from industry, no matter how they are created, contain harmful substances that may have some degree of toxicity, must be treated if their quality does not meet the legal requirements. The purpose of wastewater treatment is to remove harmful substances, thereby reducing its pollution level, and at the same time, it also has a certain economic and environmental effect. Therefore, wastewater treatment was carried out in this work by precipitation using calcium oxide to remove colloidal substances and heavy metals. Most pollutants are of organic origin and their removal will be carried in this work out using advanced oxidation processes using ozone, and ozone in combination with ultrasound to achieve water quality that complies with the law. The purification process will be optimized with respect to, method, time and amount of oxidizing agent applied. The degree of pollution of water by organic compounds will be determined on the basis of measurements of HPK, BOD and the concentration of heavy metals (lead, ferrum, chromium, copper, zinc, aluminum)

Ecologically friendly corrosion inhibitor for low alloy steels and aluminium alloys

The corrosion protective properties of environmentally friendly Ce-citrate were analyzed on AISI 4130 low alloy carbon steel and AA7075 aluminum alloy in 0.05 M NaCl solution. For this purpose different concentrations of corrosion inhibitor were analyzed in the range of 0.1-0.5 mM. Electrochemical impedance spectroscopy and potentiodynamic polarization test were used for measurements of resistance to general corrosion. Pitting potential Epit value was used for the determination of resistance to pitting corrosion. Additionally, corrosion resistance measurements and determination of pitting potential value were performed in Ce-chloride solution with the aim of comparation. SEM microscopy was used for the determination of changes on the surface of the specimens after corrosion testing. The XPS method was used for the analyses of the formed inhibitory layer on the steel specimen surface. It has been shown that significant amounts of cerium, as well as the citrate anions, are present in the inhibitory layer. Ce-citrates have proved to be an effective corrosion inhibitor for AISI 4130 steel as well as an effective pitting corrosion inhibitor for AA7075 aluminum alloy. The mechanism of action of Ce-citrate on AISI 4130 steel and AA7075 aluminum alloy has been proposed.XXIII YUCORR International Conference, 116th-19th May 2022, Divčibare, Serbia, invited talk (Bojana Radojković

Optimization of zinc dimethyldithiocarbamate synthesis process (ziram)

This work presents an optimized laboratory procedure for the synthesis of zinc dimethyldithiocarbamate (Ziram) by the reaction of the sodium salt of dimethyl dithiocarbamic acid and zinc sulfate. The reaction of synthesis of the sodium salt of dimethyl-dithiocarbamic acid takes place starting from dimethylamine, carbon disulfide and sodium hydroxide solution. To the prepared acidified aqueous solution of zinc sulphate, a solution of the sodium salt of dimethyl dithiocarbamic acid was added, whereby zinc dimethyldithiocarbamate is formed in the form of a suspension. The suspension is filtered, the filter cake is washed with water to remove the sulfate ion and dried. The structure of the obtained Ziram was confirmed by IR, 1H and 13C NMR and MS instrumental methods, and the purity was determined by the classical analytical method. The obtained product zinc dimethyldithiocarbamate was ground, formulated and used in pomiculture as fungicide under the trade name Ziram