20.500.12556/DKUM-99640 Razvoj metode kemijskega recikliranja trajnostnega kopolimera polimlečne kisline (PLeA) z uporabo zelenega katalizatorja na osnovi nanodelcev FeO Development of a chemical recycling method for a sustainable polylactic acid copolymer (PLeA) using a green FeO nanoparticle-based catalyst Diplomsko delo zajema sintezo magnetnih nanodelcev železovega oksida (FeO-MnP), njihovo površinsko funkcionalizacijo s citronsko kislino (CA) in oleinsko kislino (OA) ter preučevanje njihovega vpliva na depolimerizacijo trajnostnega kopolimera poli(mlečna kislina-ko-etilen adipat) (PLeA). Uspešnost sinteze in funkcionalizacije FeO-MnP smo potrdili s termogravimetrično analizo (TGA), infrardečo spektroskopijo s Fourierjevo transformacijo in oslabljenim popolnim odbojem (ATR-FTIR) ter testom redisperzibilnosti v ustreznem topilu. Za namen kemijskega recikliranja PLeA smo zasnovali reaktorski sistem z uporabo rotacijskega uparjalnika in lovilne pasti, ki pa se zaradi kristalizacije produkta na vratu bučke ni izkazal za optimalnega. Vpliv pripravljenih delcev na depolimerizacijo PLeA smo primerjali z referenčnim eksperimentom ob uporabi konvencionalnega katalizatorja (kositrovega(II) oktoata, Sn(Oct)₂), za katerega je v literaturi že opisana uspešna depolimerizacija do laktida, ter s kontrolnim eksperimentom brez uporabe katalizatorja. Produkte, pridobljene pri depolimerizaciji PLeA, smo ovrednotili z ATR-FTIR spektroskopijo in diferenčno dinamično kalorimetrijo (DSC). Rezultati kažejo, da prisotnost in površinska funkcionalizacija FeO-MnP vplivata na sestavo produktov depolimerizacije. Z ATR-FTIR in DSC analizami smo potrdili tvorbo laktida v produktih vseh izvedenih eksperimentov, tudi pri kontrolnem eksperimentu brez katalizatorja, pri čemer se med vzorci pojavljajo razlike v prisotnosti stranskih produktov in stopnji podobnosti z referenčnim produktom. Največja odstopanja od referenčnega laktida so bila opažena pri produktu kontrolnega eksperimenta in produktu, pridobljenem z nefunkcionaliziranimi FeO-MnP, kar nakazuje večji delež stranskih produktov. Produkti, pridobljeni z uporabo površinsko funkcionaliziranih FeO-MnP, so se po analiziranih spektralnih in termičnih značilnostih bolj približali referenci, pri čemer je največjo stopnjo podobnosti izkazal produkt, pridobljen z uporabo FeO-MnP, funkcionaliziranih s CA. Rezultati tako kažejo na potencial FeO-MnP za uporabo pri depolimerizaciji PLeA ter nakazujejo, da lahko površinska funkcionalizacija pomembno vpliva na sestavo nastalih produktov in selektivnost reakcije. Za nedvoumno ovrednotenje katalitske aktivnosti in selektivnosti bi bile potrebne nadaljnje raziskave pri primerljivih reakcijskih pogojih ter dodatna kvantitativna karakterizacija produktov. The thesis focuses on the synthesis of magnetic iron oxide nanoparticles (FeO-MnP), their surface functionalization with citric acid (CA) and oleic acid (OA), and the investigation of their effect on the depolymerization of the sustainable copolymer poly(lactic acid-co-ethylene adipate) (PLeA). The successful synthesis and functionalization of FeO-MnP were confirmed by thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy with attenuated total reflectance (ATR-FTIR), and a redispersibility test in an appropriate solvent. A reactor system based on a rotary evaporator and a collection trap was designed for the chemical recycling of PLeA; however, the system was found to be suboptimal due to product crystallization at the neck of the flask. The effect of the prepared particles on the depolymerization of PLeA was compared with a reference experiment using a conventional catalyst (tin(II) octoate, Sn(Oct)₂), for which successful depolymerization to lactide has been reported in the literature, as well as with a control experiment without a catalyst. The products obtained from the depolymerization of PLeA were evaluated by ATR-FTIR spectroscopy and differential scanning calorimetry (DSC). The results indicate that the presence and surface functionalization of FeO-MnP affect the composition of the depolymerization products. ATR-FTIR and DSC analyses confirmed the formation of lactide in the products of all experiments, including the control experiment without a catalyst, with differences among the samples observed in the presence of side products and the degree of similarity to the reference product. The greatest deviations from the reference lactide were observed for the product of the control experiment and for the product obtained using non-functionalized FeO-MnP, which indicates a higher proportion of side products. Based on their spectral and thermal characteristics, the products obtained using surface-functionalized FeO-MnP showed greater similarity to the reference product, with the product obtained using FeO-MnP functionalized with CA exhibiting the highest degree of similarity. Overall, the results thus indicate the potential of FeO-MnP for use in the depolymerization of PLeA and suggest that surface functionalization may significantly affect the composition of the resulting products and the selectivity of the reaction. Further studies under comparable reaction conditions, together with additional quantitative characterization of the products, would be required for an unambiguous assessment of catalytic activity and selectivity. nanodelci železovega oksida funkcionalizacija katalizatorji depolimerizacija polimlečna kislina poli(mlečna kislina-ko-etilen adipat) laktid iron oxide nanoparticles functionalization catalysts depolymerization polylactic acid poly(lactic acid-co-ethylene adipate) lactide true true false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-08-21 16:16:51 2026-09-07 14:00:22 2026-09-08 03:09:21 0000-00-00 00:00:00 2026 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 UN_Oblonsek_Gaja_2026.pdf UN_Oblonsek_Gaja_2026.pdf 1 7C8C852CC768C71638F9DC392094278B 0b9a2b64513f2916ed475ac777c88633265703be1a655711c896e8045272dc3b 9b773043-9f91-11f1-ab9d-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=210272 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0