Naslov: | The importance of depropagation in free radical co-polymerization of itaconates : PhD Thesis |
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Avtorji: | ID Pirman, Tomaž (Avtor) ID Likozar, Blaž (Mentor) Več o mentorju...  ID Hutchinson, Robin A. (Komentor) |
Datoteke: | DOK_Pirman_Tomaz_2024.pdf (5,03 MB) MD5: 8C5E0D7D4EC9F8ECCCBB03B70747AC54
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Jezik: | Angleški jezik |
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Vrsta gradiva: | Doktorsko delo/naloga |
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Tipologija: | 2.08 - Doktorska disertacija |
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Organizacija: | FKKT - Fakulteta za kemijo in kemijsko tehnologijo
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Opis: | Biobased monomers offer a means to enhance the sustainability of acrylic resins, which are traditionally manufactured from acrylate and methacrylate monomers derived from petrochemical sources. However, utilizing renewable feedstocks for these monomers is currently not economically viable, necessitating the exploration of alternative pathways for producing sustainable acrylic resins. Itaconates, which are produced via fermentation, share a similar structure with conventional monomers, making it possible to achieve comparable polymer properties without significantly changing production processes. However, itaconates have limitations: they depropagate at lower temperatures and exhibit much slower polymerization rates than conventional methacrylates during homopolymerization. This study explores the copolymerization of itaconates with acrylates under standard commercial conditions as a promising approach to address these challenges.
The copolymerization of dibutyl itaconate (DBI) with butyl acrylate (BA) is examined in detail. Initial investigations involved batch homopolymerizations of DBI, varying monomer and initiator concentrations, solvent types, and reaction temperatures to validate known propagation and termination kinetics and to gain a deeper understanding of DBI depropagation. Conversion rates and molecular weight distributions were measured using 1H NMR and size exclusion chromatography, respectively. These results were used to refine the representation of depropagation kinetics by fitting the data to a comprehensive kinetic model of DBI homopolymerization, implemented in the PREDICI software, with additional kinetic parameters sourced from recent literature.
Subsequently, BA was employed as a highly reactive, non-depropagating comonomer in a batch system to mitigate the strong depropagation and slow polymerization rates of DBI. Experiments were conducted with varying initial monomer concentrations and compositions at different temperatures. In addition to demonstrating that BA significantly enhances the polymerization rate, the data provided initial estimates of reactivity ratios for acrylate-itaconate copolymerization.
Furthermore, semi-batch copolymerization experiments were performed with varying monomer compositions under starved feed conditions and elevated temperatures, reflecting typical commercial practices. These trials indicated that resins containing up to 50% itaconate are feasible for production, offering the potential to greatly increase the sustainable content of acrylic polymer resins.
Finally, a comprehensive kinetic model for BA/DBI copolymerization, incorporating itaconate depropagation and acrylate backbiting, was developed using the PREDICI software. The model's predictions are compared to experimental batch and semi-batch conversion profiles, polymer molar mass distributions, and comonomer composition drift profiles. This comparison enhances the understanding of the system and provides a tool for further process development and optimization of operating conditions. |
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Ključne besede: | Itaconates, Bio-based monomer, Kinetic modeling, Sustainable acrylic resins, Depropagation |
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Kraj izida: | Maribor |
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Kraj izvedbe: | Maribor |
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Založnik: | [T. Pirman] |
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Leto izida: | 2024 |
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Št. strani: | Str. XVIII-135 |
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PID: | 20.500.12556/DKUM-90625  |
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UDK: | 66.095.26.011:678.744.32(043.3) |
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COBISS.SI-ID: | 226037507  |
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Datum objave v DKUM: | 12.02.2025 |
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Število ogledov: | 0 |
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Število prenosov: | 9 |
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Metapodatki: |  |
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Področja: | KTFMB - FKKT
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PIRMAN, Tomaž, 2024, The importance of depropagation in free radical co-polymerization of itaconates : PhD Thesis [na spletu]. Doktorska disertacija. Maribor : T. Pirman. [Dostopano 13 april 2025]. Pridobljeno s: https://dk.um.si/IzpisGradiva.php?lang=slv&id=90625
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