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High entropy oxides: synthesis and application
No full textVisoko-entropijski oksidi su kristalični materijali kojima su kationi nasumično raspoređeni u kristalnoj rešetki, što omogućava njihovo lako modificiranje za potrebe tehnologije, te su vrlo stabilni zahvaljujući visokoj entropiji. Prva ih je sintetizirala Christina M. Rost i njen tim 2015. u potrazi za novim naprednim materijalima koji bi mogli zadovoljiti tehnološke potrebe. Sastavljeni su od 5 ili više komponenti, tj. kationa u rešetki, zbog toga što veći broj komponenti povećava entropiju sustava. To omogućava veću stabilnost sustava što je posebno značajno pri visokim temperaturama, pri kojima se često javljaju strukturne nestabilnosti. Visoka entropija ujedno omogućava reverzibilan prijelaz sustava iz višefaznog u jednofazno stanje i obrnuto. Posebni značaj ovih materijala je njihova primjena u dobivanju obnovljivih oblika energije i smanjenju korištenja toksičnih kemikalija, čime doprinose očuvanju planete.High-entropy oxides are crystalline materials that lack a regular arrangement of cations in the crystal lattice, which allows their easy modification to meet technological requirements. They are highly stable due to their high entropy. Christina M. Rost and her team first synthesized them in 2015 while searching for new advanced materials to meet technological demands. These oxides are composed of 5 or more components, i.e., cations in the lattice, as a higher number of components increases the entropy value of the system, providing greater stability. This is particularly significant at high temperatures where instabilities often occur. The high entropy also enables the reversibility of the system from multiphase to single-phase states and vice versa. The significance of these materials lies in their application for renewable energy sources and the reduction of toxic chemical usage, contributing to the preservation of the planet
Methods for separation of azeotropes
No full textAzeotropne smjese vrlo su česte u kemijskim procesima, a za njihovu separaciju koriste se mnoge metode. Neke od tih metoda zahtijevaju veliki utrošak energije i trošak zbrinjavanja štetnih otapala, stoga se za separaciju komponenti koriste „salt-out“ metode, tj. metode isoljavanja, kao i ekstrakcija pomoću niskotemperaturnih eutektičkih otapala („deep eutectic solvents“). U ovom radu istražena je mogućnost separacije sustava acetonitril-voda,
2-propanol-voda, etanol-voda, heksan-etanol u odabranim masenim odnosima metodom ekstrakcije uz primjenu raznih DES-ova i salt-out metodom.Azeotropic mixtures are very common in chemical processes, and many methods are used for their separation. Some of these methods require a large expenditure of energy and the cost of disposing of harmful solvents, therefore "salt-out" methods, i.e. salting out methods, as well as low-temperature eutectic solvents ("deep eutectic solvents") are used for the separation of components. In this work, the possibility of separating the solutions of acetonitrile-water, 2-propanol-water, ethanol-water, hexane-ethanol in selected mass ratios and the extraction method with the application of different DESs as well as the salt-out method was investigated
Decomposition of neonicotinoids in an annular photoreactor
No full textNeonikotinoidni insekticidi predstavljaju najvažniju novu klasu sintetskih insekticida. Zahvaljujući svojim fizikalno-kemijskim svojstvima te visokoj selektivnosti i učinkovitosti smatraju se odgovarajućom alternativom tradicionalnim pesticidima, no karakterizira ih izrazita postojanost i laka prenosivost u svim okolišnim medijima. Iako se općenito smatraju sigurnima za ljude u niskim koncentracijama, provedena istraživanja ukazuju na njihov dugoročni potencijal za genotoksičnost, citotoksičnost, oslabljenu imunološku funkciju i reprodukciju te urođene mane, kao i akutne zdravstvene učinke u smislu respiratornih, kardiovaskularnih i neuroloških simptoma. Kako bi se smanjili rizici za okoliš i ljudsko zdravlje, potrebno je primijeniti različite tehnologije njihova uklanjanja iz vode, pri čemu se obično primjenjuju različiti fizikalno-kemijski i biološki postupci. Obzirom da ih konvencionalne tehnologije za pročišćavanje voda ne mogu učinkovito ukloniti, javila se potreba za razvojem i primjenom naprednijih tehnologija za njihovo uklanjanje, kao što su napredni oksidacijski procesi, među kojima se posebno ističe heterogena fotokataliza. U ovome radu ispitivana je fotokatalitička razgradnja neonikotinoidnog insekticida imidakloprida u anularnom fotoreaktoru s recirkulacijom reakcijske smjese primjenom lampe Arcadia 8W, koja predstavlja simulaciju Sunčevog zračenja. Pri tome je ispitivan utjecaj triju procesnih varijabli – početne koncentracije imidakloprida (5, 10, 15 ppm), količine suspendiranog čistog
TiO2 P25 (2, 4, 6 mg) te pH vrijednosti reakcijske smjese (4, 6,5, 9), a tijek fotorazgradnje praćen je analitičkom metodom tekućinske kromatografije visoke djelotvornosti (HPLC). Dobiveni eksperimentalni podatci testirani su na pretpostavljeni kinetički model (kinetiku reakcije pseudo-prvoga reda izvedenu iz Langmuir-Hinshelwoodovog kinetičkog modela) te je pomoću programskog paketa Design-Expert primjenom ANOVA metode definiran model istraživanoga procesa, pri čemu je predložen kvadratni model. Eksperimentalni rezultati pokazali su da sva tri ispitivana parametra značajno utječu na učinkovitost fotokatalitičke razgradnje imidakloprida, pri čemu je njegova početna koncentracija najznačajniji parametar, nakon čega slijedi količina TiO2, dok pH vrijednost predstavlja najmanje značajan parametar. Najveća učinkovitost procesa postignuta je pri koncentraciji imidakloprida 5 ppm, količini TiO2 4 mg te pH vrijednostima 6,5 i 9.Neonicotinoid insecticides are the most important new class of synthetic insecticides. Due to their physicochemical properties, high selectivity and high efficacy, they are considered a suitable alternative to conventional pesticides, but are also very stable and easily transferable in all environmental media. Although they are generally considered safe for humans at low concentrations, research indicates their long-term potential for genotoxicity, cytotoxicity, impairment of immune function and reproduction, as well as birth defects and acute health effects in the form of respiratory, cardiovascular and neurological symptoms. In order to reduce the risks to the environment and human health, various technologies must be used to remove these substances from water, usually using different physico-chemical and biological processes. Since conventional water purification technologies are not sufficient to effectively remove them, more advanced technologies for their removal need to be developed and applied, such as advanced oxidation processes, among which heterogeneous photocatalysis stands out. In this work, the photocatalytic degradation of the neonicotinoid insecticide imidacloprid was investigated in a ring-shaped photoreactor with recirculation of the reaction mixture using an Arcadia 8W lamp simulating solar radiation. The influence of three process variables was investigated – the initial concentration of imidacloprid (5, 10, 15 ppm), the amount of suspended pure TiO2 P25 (2, 4, 6 mg) and the pH of the reaction mixture (4, 6.5, 9). The course of photodegradation was monitored using the analytical method of high-performance liquid chromatography (HPLC). The experimental data obtained were tested with the assumed kinetic model (pseudo-first-order reaction kinetics, derived from the Langmuir-Hinshelwood kinetic model). The model of the investigated process was created using the Design Expert software and the ANOVA method, where a quadratic model was proposed. The experimental results showed that all three parameters tested had a significant effect on the efficiency of photocatalytic degradation of imidacloprid, with the initial concentration being the most significant parameter, followed by the amount of TiO2, while pH was the least significant parameter. The highest efficiency of the process was achieved at an imidacloprid concentration of 5 ppm, a TiO2 amount of 4 mg and pH values of 6.5 and 9
Synthesis of a new azalide derivative on an enlarged scale
No full textAzalidi predstavljaju skupinu makrolidnih antibiotika u čiji je makrociklički laktonski prsten uveden dušikov atom čime su poboljšana mnoga njihova biološka svojstva. Najpoznatiji predstavnik ove skupine je azitromicin, 9-deokso-9-dihidro-9a-metil-9a-aza-9a-homoeritromicin A. Azalidi posjeduju brojne slobodne hidroksilne skupine koje su pogodne za uvođenje raznih supstituenata i sintezu novih spojeva. Uvođenjem zaštitnih skupina na pojedina reaktivna mjesta na molekuli moguće je sintetizirati željeni spoj. U ovom radu opisana je višestupnjevita sinteza novog azalidnog derivata na uvećanoj skali. Pripravljeni su prekursori koji će poslužiti za pripravu novih potencijalno aktivnih derivata azalida. U prvom stupnju sinteze, demetiliranjem 9-deokso-9a-aza-9a-homoeritromicina A na položaju 3’-N- pripravljen je 3'-N-demetil-9-deokso-9a-aza-9a-homoeritomicin A (2). Uvođenjem benziloksikarbonilne zaštitne skupine na dušikove atome, sintetiziran je 9a,3'-N,N-dibenziloksikarbonil-9-deokso-9a-aza-9a-homoeritromicin A (3). U sljedećem stupnju, reakcijom acetiliranja spoja 3 dobiven je 11,2',4''-O-triacetil-9a,3'-N,N-dibenziloksikarbonil-9-deokso-9a-aza-9a-homoeritromicin A (4). Zatim, reakcijom spoja 4 s etilkloroksoacetatom i uz 4-dimetilaminopiridin (DMAP) kao katalizator priređen je 11,2’,4’’-O-triacetil-9a,3’-N,N-dibenziloksikarbonil-12-O-(2-etoksi-2-okso-acetil)-9-deokso-9a-aza-9a-homoeritromicin A (5). U posljednjem stupnju sinteze kiselinskog derivata, hidrolizom spoja 5 pripravljen je 11,2’,4”-O-triacetil-9a,3’-N,N-dibenziloksikarbonil-12-O-oksalooksi-9-deokso-9a-aza-9a-homoeritromicin A (7). Također, katalitičkim hidrogeniranjem spoja 5 sintetiziran je 11,2’,4’’-O-triacetil-9a,3’-N,N-demetil-12-O-(2-etoksi-2-okso-acetil)-9-deokso-9a-aza-9a-homoeritromicin A (8). Strukturna i spektroskopska karakterizacija novopriređenih spojeva provedena je 1H i 13C NMR spektroskopijom.Azalides represent a group of macrolide antibiotics whose macrocyclic lactone ring has a nitrogen atom introduced, which improves many of their biological properties. The best-known representative of this group is azithromycin, 9-deoxo-9-dihydro-9a-methyl-9a-aza-9a-homoerythromycin A. Azalides possess numerous free hydroxyl groups that are suitable for the introduction of various substituents and the synthesis of new compounds. By introducing protective groups to individual reactive sites on the molecule, it is possible to synthesize the desired compound. This paper describes a multi-step synthesis of a new azalide derivative on an enlarged scale. Precursors have been prepared and they will be used for the preparation of new potentially active azalide derivatives. In the first stage of synthesis, 3'-N-demethyl-9-deoxo-9a-aza-9a-homoerythromycin A (2) was prepared by demethylating 9-deoxo-9a-aza-9a-homoerythromycin A at the 3'-N- position. By introducing a benzyloxycarbonyl protecting group on nitrogen atoms, 9a,3'-N,N-dibenzyloxycarbonyl-9-deoxo-9a-aza-9a-homoerythromycin A (3) was synthesized. In the next step, the acetylation reaction of compound 3 gave 11,2',4''-O-triacetyl-9a,3'-N,N-dibenzyloxycarbonyl-9-deoxo-9a-aza-9a-homoerythromycin A (4). Then, by reaction of compound 4 with ethyl chloroxoacetate and with 4-dimethylaminopyridine (DMAP) as a catalyst, 11,2',4''-O-triacetyl-9a,3'-N,N-dibenzyloxycarbonyl-12-O-(2-ethoxy-2-oxo-acetyl)-9-deoxo-9a-aza-9a-homoerythromycin A (5) was prepared. In the last stage of the synthesis of the acid derivative, 11,2',4”-O-triacetyl-9a,3'-N,N-dibenzyloxycarbonyl-12-O-oxalooxy-9-deoxo-9a-aza-9a (7) was prepared by hydrolysis of compound 5. Also, 11,2',4''-O-triacetyl-9a,3'-N,N-demethyl-12-O-(2-ethoxy-2-oxo-acetyl)-9-deoxo-9a-aza-9a-homoerythromycin A (8) was prepared by catalytic hydrogenation of compound 5. Structural and spectroscopic characterization of the newly prepared compounds was carried out by 1H and 13C NMR spectroscopy
Chemometric classification of psychoactive samples
No full textU ovom radu provedena je klasifikacija uzoraka opojnih droga upotrebom umjetnih neuronskih mreža. Za potrebe istog, najprije je provedena optimizacija mreža: određen je tip mreže, broj neurona u skrivenom sloju, te aktivacijska i funkcija za treniranje. Najboljim se pokazao višeslojni linearni perceptron s 12 neurona u skrivenom sloju, tangens hiperbolnom aktivacijom, treniran funkcijom konjugiranog gradijenta uz visku točnost od 84,93% ispravnog predviđanja na nezavisnom (vanjskom) setu varijabli. Umjetne neuronske mreže pokazale su se kao brz i pouzdan alat kojim može ostvariti kvalitetna klasifikacija uzoraka opojnih droga te kao takve sigurno imaju svijetlu perspektivu u rasvjetljavanju kriminalnih djelatnosti vezanih uz transfer opojnih droga.The classification of samples of narcotic drugs using artificial neural networks is shown in this paper. For the same purpose, network optimization was first implemented: a network type was determined, a number of neurons within the hidden layer, also an activation and training functions were determined. The best solution is multilayer linear perceptron with 12 neurons within the hidden layer, with tangent hyperbolic activation function, trained with conjugated gradient function in the high accuracy of 84.93% of the correct prediction on the independent (external) set of variables. Artificial neural networks have proven to be a fast and reliable tool that can achieve a high-quality classification of narcotic drugs samples and certainly have a bright perspective on the illicit trafficking of narcotic drugs
Development and characterisation of Zn-ion battery based on V2O5
No full textU ovom radu provedena je karakterizacija reduciranog grafenova oksida (rGO) u troelektrodnom sustavu. Također, provedena je sinteza i karakterizacija rGO papira. Cilj rada bio je dobiti fleksibilan samostojeći materijal pogodan za depoziciju cinka. U tu svrhu priređen je rGO papir s ugrađenim ugljikovim nanocjevčicama (CNT) postupkom elektrokemijske redukcije pri -1,4 V. rGO/CNT papir upotrijebljen je kao anoda u cink-ionskoj bateriji uz rGO/V2O5 papir kao katodu. Karakterizacija baterije provedena je metodama kronoamperometrije (CA), cikličke voltametrije (CV) i elektrokemijske impedancijske spektroskopije (EIS). Na dobivenim cikličkim voltamogramima zabilježeni su strujni vrhovi koji odgovaraju taloženju/otapanju cinka te strujni vrhovi koji odgovaraju redoks reakciji V2O5. Vrijednosti specifičnog kapaciteta, Cs, rGO-CNT-Zn/rGO-V2O5 baterije dobivene metodom CV kreću se od 30,16 mAh g^-1 do 172,53 mAh g^-1 . Također, proveden je galvanostatski proces punjenja i pražnjenja baterije. Tom metodom dobiveni su specifični kapaciteti u rasponu od 1,83 mAh g^−1 pri najvećoj jakosti struje do 170,13 mAh g^−1 pri najmanjoj vrijednosti struje. Prije nego što je ispitana baterija, provedena je i karakterizacija elektroda (rGO, rGO/CNT, rGO/MXene i rGO/V2O5) u troelektrodnom sustavu koristeći pri tome kronoamperometriju za redukciju GO i cikličku voltametriju kako bi se deponirao cink na rGO i rGO modificiranim slojevima nanesenima na elektrodu staklastog ugljika (GC).In this work, reduced graphene oxide (rGO) was charachterised in three-electrode system. Synthesis and characterization of rGO paper was also carried out. The aim of the work was to obtain a flexible free-standing material suitable for zinc deposition. For this purpose, rGO paper containing carbon nanotubes (CNT) was prepared by electrochemical reduction at -1.4 V. rGO/CNT paper was used as the anode in a zinc-ion battery while rGO/V2O5 paper was used as the cathode. Characterization of the battery was carried out using chronoamperometry (CA), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. In the resulting cyclic voltammograms, current peaks corresponding to the deposition/dissolution of zinc and current peaks corresponding to the redox reaction of V2O5 were recorded. The values of the specific capacity, Cs, of
rGO-CNT-Zn/rGO-V2O5 batteries obtained by the CV method range from 30.16 mAh g^-1 to 172.53 mAh g^-1. Also, a galvanostatic process of charging and discharging the battery was carried out. Using this method, specific capacities ranging from 1.83 mAh g^−1 to
170.13 mAh g^−1 were recorded. Before the battery was tested, the rGO electrodes containing CNT, MXene or V2O5 (rGO, rGO/CNT, rGO/MXene and rGO/V2O5) were characterized in a three-electrode system. Reduction of GO was carried out by chronoamperomertry and Zn deposition at rGO, rGO/CNT and rGO/MXene electrodes was carried out by cyclic voltametry
Assessment of the air quality index for particle matter PM10 and PM2.5 in the city of Zagreb using machine learning methods
No full textOnečišćenje zraka predstavlja veliki problem današnjice, kako za okoliš tako i za ljudsko zdravlje. Zato je cilj ovog diplomskog rada razviti modele za procjenu dnevnog indeksa kvalitete zraka (AQI) koji se odnosi na onečišćenje vanjskog zraka lebdećim česticama PM10 i PM2,5 (lebdeće čestice ekvivalentnog aerodinamičnog promjera manjeg od 10 i 2,5 μm) koristeći metode nadziranog strojnog učenja temeljene na klasifikaciji. Za razvoj modela primijenjene su metoda nasumičnih šuma i metoda potpornih vektora, koristeći programski jezik Python i pripadajuće knjižice. Korišteni su podaci o masenim koncentracijama frakcija lebdećih čestica PM10 i PM2,5 i meteorološki podaci s tri mjerne postaje državne mreže za trajno praćenje kvalitete zraka. Uz lokalne dnevne meteorološke podatke korišteni su i dnevni podaci prikupljeni na meteorološkoj postaji Maksimir, Državnog hidrometeorološkog zavoda. Za izradu modela korišteni su prikupljeni i izračunati srednji dnevni meteorološki i generirani temporalni podaci. U Pythonu su izračunati i uspoređeni kriteriji vrednovanja razvijenih klasifikacijskih modela. Za korištene podatke za procjenu dnevnog indeksa kvalitete zraka modeli nasumičnih šuma pokazuju bolje rezultate i performanse u odnosu na model potpornih vektora. Oba razvijena modela pokazuju zadovoljavajuću točnost (oko 90%) te se u budućnosti mogu primijeniti za predviđanje indeksa kvalitete zraka na novim skupovima podataka. Točno predviđanje indeksa kvalitete zraka može pridonijeti pravovremenom donošenju učinkovitih mjera za poboljšanje kvalitete zraka.Air pollution is a critical issue of today, both for the environment and for human health. Therefore, the aim of this final thesis is to develop models for estimating the daily air quality index (AQI) related to outdoor air pollution by particulate matter PM10 and PM2,5 (particulate matter with an equivalent aerodynamic diameter of less than 10 and 2.5 μm) using methods of monitored machine learning based on classification. Random Forest method and Support Vector Machine method were applied for the development of the model, using the Python programming language and associated libraries. The theses used data on mass concentrations of fractions of particulate matter PM10 and PM2,5 and meteorological data from three measuring stations of the state network for permanent monitoring of air quality. In addition to local daily meteorological data, daily data collected at the Maksimir meteorological station of the State Hydrometeorological Institute were also used. Collected and calculated average daily meteorological and generated temporal data were used to create the model. Validation metrics, evaluation criteria of the developed classification models, were calculated and compared in Python. For the data used to estimate the daily Air Quality Index, the Random Forest models show better results and performance compared to the Support Vector Machine models. Both developed models show satisfactory accuracy (around 90%) and can be applied in the future to predict Air Quality Index on new data sets. Accurate prediction of the Air Quality Index can contribute to timely adoption of effective measures to improve air quality
Solubility testing of poly(lactic acid) in organic solvents
No full textPoli(mliječna kiselina) je često korišten polimer u brojnim industrijama zbog svoje biorazgradljivosti i dobrih svojstava. Iz navedenog razloga važno je pozornost usmjeriti na istraživanja sustava polimer-otapalo u svrhu poboljšavanja svojstava polimera te predviđanja njihove topljivosti. U ovom radu ispitivana je topljivost poli(mliječne kiseline) medicinske i tehničke čistoće u 12 različitih otapala: metanol, etanol, aceton, etil-metil-keton, etil acetat, kloroform, tetraklormetan, cikloheksanon, toluen, tetrahidrofuran, 1,4-dioksan i demineralizirana voda. Topljivost je ispitivana na sobnoj temperaturi s i bez miješanja, te na 40, 50 i 60 °C s miješanjem. Određen je Hansenov parametar topljivosti za poli(mliječnu kiselinu) medicinske čistoće, te je grafički prikazan tzv. volumen topljivosti.Poly(lactic acid) is a commonly used polymer in various industries due to its biodegradability and favorable properties. For this reason, it is important to focus on researching polymer- solvent systems to enhance polymer properties and predict their solubility. In this work, the solubility of poly(lactic acid) of medical and technical grade was tested in 12 different solvents: methanol, ethanol, acetone, ethyl methyl ketone, ethyl acetate, chloroform, tetrachloromethane, cyclohexanone, toluene, tetrahydrofuran, 1,4-dioxane, and demineralized water. The solubility was tested at room temperature with and without stirring, as well as at 40, 50, and 60°C with stirring. The Hansen solubility parameter for medical-grade poly(lactic acid) was determined, and the “solubility volume” was graphically represented
Polyethylene furanoate (PEF) - polymer of the future: properties, advantages and potential application
No full textPlastika predstavlja neizostavni dio suvremenog društva, s proizvodnjom koja raste brže od bilo kojeg drugog masovnog materijala. Unatoč tome, vrlo mali postotak proizvedene plastike završava u reciklaži, dok veliki dio plastičnog otpada, koji se ne može reciklirati, završava u prirodi, gdje mu za potpunu razgradnju može trebati desetljećima ili čak stoljećima. Poli(etilen-tereftalat) (PET) je drugi najčešće korišteni polimer u plastici i najviše recikliran polimer u Europi. Međutim, današnja istraživanja su usmjerena prema poli(etilen-furanoatu) (PEF), potencijalnoj bio-baznoj alternativi za PET. Pregledni rad fokusira se na sintezu PEF-a polimerizacijom iz 2,5-furandikarboksilne kiseline s etilen-glikolom. Analiziraju se svojstva PEF-a, uključujući toplinska i mehanička svojstva, te se ističu prednosti u odnosu na PET, kao što su bolja barijerna svojstva za plinove. Nadalje, razmatra se primjena PEF-a u ambalaži hrane s duljim vijekom trajanja te njegova potencijalna zamjena za staklene boce, limenke i višeslojne boce za pivo i sokove. Također, analiziraju se ključni načini recikliranja PEF-a, čime se dodatno naglašava njegova vrijednost u kontekstu kružnog gospodarstva i smanjenja plastičnog otpada.Plastic represents an indispensable part of modern society, with production growing faster than any other mass material. Despite this, a very small percentage of produced plastic ends up being recycled while a large portion of non-recyclable plastic waste ends up in nature. There it can take decades or even centuries to fully decompose.
Poly(ethylene-terephthalate) (PET) is the second most commonly used polymer in plastics and the most recycled polymer in Europe. As an answer, current research is focusing on poly(ethylene-furanoate) (PEF), a potential bio-based alternative to PET. This review focuses on the synthesis of PEF by polymerization from 2,5-furandicarboxylic acid with ethylene glycol. The mechanical and thermal properties of PEF are analyzed, and its advantages over PET, such as better gas barrier, are highlighted. Furthermore, the application of PEF in food packaging with a longer shelf life and its potential replacement for glass bottles, cans, and multilayer bottles for beer and juices are considered. Key methods of recycling PEF are also analyzed, further emphasizing its value in the context of a circular economy and reducing plastic waste
Preparation and characterization of blends of polylactic acid with a new biodegradable medium-chain-length polyhydroxyalkanoate
No full textGotovo polovica globalne proizvodnje plastike primjenjuje se u svrhu proizvodnje ambalaže za pakiranje hrane. Korištenje polimera na bazi fosilnih goriva koji nisu biorazgradljivi rezultira velikim ekološkim posljedicama. Glavni nedostatak sintetskih polimera jest nagomilavanje plastičnog otpada u okolišu što rezultira velikim ekološkim posljedicama. Iako su poznate brojne metode za gospodarenje otpadom, polimeri na bazi fosilnih goriva teško podliježu biorazgradnji ili recikliranju. Biorazgradljivi polimeri poput poli(mliječne kiseline) (PLA) i
poli(3-hidroksibutirat-ko-3-hidroksivalerata) (PHBV) pokazali su se kao moguća alternativa za takve sintetske i teško razgradljive polimere. Obzirom na slabija funkcionalna svojstva pojedinih polimera poput PLA i PHBV, daje se naglasak polimernim mješavinama s ciljem razvoja poboljšanih svojstava čistih polimera. U ovom radu ispitana su svojstva polimernih mješavina na bazi PLA i PHBV s udjelom PLA od 65, 70, 75, 80 i 85 mas. % te čistih uzoraka. Pretražnom elektronskom mikroskopijom (SEM) utvrđena je homogena struktura polimernih mješavina kao rezultat međufazne adhezije između PLA i PHBV. Promjene u kemijskoj strukturi i informacije o kemijskom sastavu dobivene su FTIR-ATR tehnikom te je utvrđeno međudjelovanje između PLA i PHBV u mješavinama obzirom na pomake apsorpcijskih vrpci. Mjerenjem kontaktnog kuta s vodom potvrđena je hidrofobnost površina svih uzoraka. Toplinska svojstva ispitana su diferencijalnom pretražnom kalorimetrijom (DSC) i termogravimetrijskom analizom (TGA). DSC analizom utvrđena je djelomična mješljivost polimernih mješavina te da PHBV pogoduje kristalizaciji PLA. TGA analizom određena je toplinska razgradnja polimernih mješavina koja se odvija u dva stupnja. Također, povećanjem udjela PLA (od 80 mas. % PLA) toplinska stabilnost PLA/PHBV polimernih mješavina se povećava. Vrijednosti propusnosti vodene pare uzoraka polimernih mješavina nalaze se između vrijednosti čiste PLA i PHBV te porastom udjela PHBV (od 25 mas. % PHBV) poboljšavaju se barijerna svojstva PLA/PHBV polimernih mješavina.Almost half of the global production of plastic is used to produce food packaging. The use of fossil fuel-based polymers that are not biodegradable results in major environmental consequences. The main disadvantage of synthetic polymers is the accumulation of plastic waste in the environment, which results in major environmental consequences. Although numerous methods are known for waste management, polymers based on fossil fuels are difficult to biodegrade or recycle. Biodegradable polymers such as poly(lactic acid) (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) have proven to be a possible alternative for such synthetic and difficult-to-degrade polymers. Considering the weaker functional properties of certain polymers such as PLA and PHBV, emphasis is given to polymer blends to develop improved properties of pure polymers. In this work, the properties of polymer blends based on PLA and PHBV with a PLA content of 65, 70, 75, 80, and 85 wt. % were investigated. Scanning electron microscopy (SEM) revealed a homogeneous structure of the polymer blends due to interfacial adhesion between PLA and PHBV. Changes in the chemical structure and information on the chemical composition were investigated by the FTIR-ATR technique, and the interaction between PLA and PHBV in the blends was determined by the shifts of the absorption bands. By measuring the contact angle with water, the hydrophobicity of the surface of all samples was confirmed. Thermal properties were tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC analysis revealed partial miscibility of polymer blends and that PHBV favors the crystallization of PLA. TGA analysis determined the thermal decomposition of polymer blends, which takes place in two stages. Also, by increasing the proportion of PLA (from 80 wt. % PLA), the thermal stability of PLA/PHBV polymer blends increases. The values of water vapor permeability of polymer blend samples are between the values of pure PLA and PHBV, and increasing the proportion of PHBV (from 25 wt. % PHBV) improves the barrier properties of PLA/PHBV polymer blends