Preparation of Synthetic and Natural Porous Polymers via Multiphase Media

doctoral dissertation

Stanko Kramer (Author), Peter Krajnc (Mentor)

Abstract

PolyHIPEs are highly porous polymers with an interconnecting porous structure. They have found usage in the removal of pollutants, water clean-up, oil spill removal, catalysis, controlled release of active compounds, wound dressing and tissue engineering. The wide applicability of polyHIPEs is possible through their inherent porosity and chemical diversity. The aim of this dissertation was to increase the chemical diversity of polyHIPEs, develop an efficient method for the synthesis of polyHIPE beads and to use natural resources for the synthesis of polyHIPEs, subsequently, paving the pathway to more sustainable synthetic procedures. PolyHIPEs tend to have poor mechanical properties, therefore, it was crucial to investigate the influence of the internal phase volume, initation type (photo vs thermal) and monomer functionality on the mechanical and morphological properties of thiol-ene polyHIPEs. The results show that the main factors influencing the morphological and mechanical properties are the monomer structure and the internal phase volume. Besides the inherent porosity and chemical versatility typical of polyHIPEs, they can also be produced in various shapes, e.g., monoliths, membranes and beads. Therefore, the dissertation also focuses on the synthesis of polyHIPE beads. The polyHIPE beads were produced through the usage of water-in-oil-in-water (W/O/W) multiple emulsions. To enable the synthesise of open porous polyHIPE beads, thiol-ene polymerisation was combined with photopolymerisation to guarantee a rapid polymerisation prior the break-down of the multiple emulsion. Consequently, it was possible to synthesise polyHIPE beads. The first study showed that by altering the thiol to acrylate ratio in favour of the acrylate the degradation rate of the synthesised polyHIPE beads gets reduced. Additionally, it was demonstrated that the beads can be readily functionalised with allyl amine and used for the adsorption of methylene blue (12.0 mg/g in 24 hours). The next study combined polyHIPE beads with magnetic nanoparticles (MNPs) to produce magnetic polyHIPE beads which were used for the removal of Pb2+. To produce the magnetic polyHIPE beads, magnetic nanoparticles (MNPs) were added to the organic phase. The MNPs get incorporated into the polymer-network after the polymerisation, therefore, forming magnetic polyHIPE beads. The MNPs were shown to influence the morphology and the size of the beads. Additionally, the polyHIPE beads were shown to remove up to 97.0 % of Pb2+ after 24 hours from a 2.9 mg/L solution of Pb2+. In the last study related to the synthesis of polyHIPE beads, functional polyHIPE beads were produced and then functionalised to enable the binding of the enzyme invertase. These beads were then utilised for the hydrolysis of sucrose. The conversion of sucrose to glucose and fructose was 100% after 60 minutes for the polyHIPE beads, while the conversion for non-porous beads was only 6.5%. The last part of the thesis focused on more sustainable/natural approaches to polyHIPE synthesis. The first study utilised limonene as a replacement to conventional solvents (e.g., cyclohexane) in the production of O/W HIPEs and the polymerisation thereof into polyHIPEs. It was shown that limonene can be used as an efficient replacement in the production of polyHIPEs. The next study used natural resources (terpenoids) which were modified to contain polymerisable units, which were used for the synthesis of terpenoid-based polyHIPEs. The synthesised monomers were then crosslinked with 5 and 10 mol. % TMPTA to form polyHIPEs, consequently producing porous polymers. The last study in this thesis used the terpenes limonene, carvone and myrcene to produce bio-based polyHIPEs by utilising multifunctional acrylates (PETA and TMPTA) as the comonomers. This study demonstrates that it is possible to prepare polyHIPEs from commercially available terpenes, therefore, moving the field of polyHIPEs into a more sustainable direction.

Keywords

HIPE;PolyHIPE;Multiple Emulsions;Functional polyHIPEs;Natural Polymers;Terpenes;

Data

Language:	English
Year of publishing:	2023
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[S. Kramer]
UDC:	66.095.262(043.3)
COBISS:	177042179
Views:	12
Downloads:	2
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary title:	Priprava sintetičnih in naravnih poroznih polimerov iz večfaznih medijev
Secondary abstract:	PoliHIPE material so visoko porozni polimeri za katere je značilna povezovalna struktura sestavljena iz primarnih in sekundarnih por. Prav ta značilna struktura omogoča uporabo na številnih različnih področjih, kot je odstranjevanje onesnaževalcev iz okolja, čiščenje vod, odstranjevanje nafte, kataliza, kontrolirano sproščanje učinkovin, biomedicina in tkivno inženirstvo. Široka uporabnost poliHIPE materialov je možna zaradi njihove značilne poroznosti in kemijske raznolikosti. Kljub temu, da imajo poliHIPE materiali že visoko raznolikost, je bil cilj disertacije povečati le-to, razviti učinkovito metodo za sintezo poliHIPE kroglic in uporabiti naravne vire za sintezo poliHIPE materialov. PoliHIPE materiali imajo zaradi svoje visoke poroznosti običajno slabe mehanske lastnosti. Zato smo v disertaciji preučevali vpliv volumna notranje faze, vrste iniciacije in funkcionalnosti monomerov na mehanske in morfološke lastnosti tiol-en poliHIPE materialov. Glede na rezultati, so glavni dejavniki, ki vplivajo na morfološke in mehanske lastnosti struktura monomerov in delež oz. volume notranje faze. Poleg kemijske raznolikost in značilne poroznosti, je mogoče pripraviti poliHIPE materiale v različnih oblikah, npr. monolite, membrane in kroglice. Posledično, se bomo ukvarjali tudi z pripravo poroznih kroglic, saj je sferična oblika ugodna za določene aplikacije. PoliHIPE kroglice smo pripravili z uporabo t.i. multiplih emulzij tipa voda-v-olju-v-vodi (V/O/V). Da bi zagotovili pripravo odprtoporoznih poliHIPE kroglic, smo uporabili tiol-en kemijo in fotopolimerizacijo, saj smo s tem zagotovili, da pride do polimerizacije pred razpadom emulzije. V naslednji raziskavi smo v postopek priprave poliHIPE kroglic vključili magnetne nanodelce, da bi pripravili magnetne poliHIPE kroglice. To smo naredili tako, da smo magnetne nanodelce dali v organsko/monomerno fazo. Med polimerizacijo monomerov, se magnetni nanodelci vključijo v polimerno strukturo, kar pa vodi do nastanka poliHIPE materialov z magnetnimi lastnostmi. V zadnji raziskavi povezani s sintezo poliHIPE kroglic, smo pripravili funkcionalne poliHIPE kroglice s prostimi hidroksilnimi skupinami. Pripravljene kroglice smo funkcionalizirali, da bi omogočili kovalentno vezavo encima invertaza. Pripravljene nosilce smo nato uporabili za katalizo hidrolize saharoze v glukozo in fruktozo. Zadnji del disertacije se osredotoča na bolj trajnostne/naravne pristope k sintezi poliHIP materialov. V prvi raziskavi smo uporabili limonen kot nadomestilo bolj konvencionalnim topilom (npr. cikloheksan) za pripravo O/V HIP emulzij in polimerizacijo le-teh v poliHIPE materiale. Primerjava limonena s cikloheksanom je pokazala, da je limonen odlična alternativa cikloheksanu kot notranji fazi. Z namenom povečanja trajnosti in uporabe naravnih virov, smo v nadaljevanju uporabili t.i. terpenoide. Te molekule smo modificirali, da bi pridobili monomere, ki jih lahko polimeriziramo in tvorimo poliHIPE materiale na osnovi terpenoidov. Sintetizirane monomere smo zamrežili z uporabo akrilata in tvorili materiale s tipično poliHIPE strukturo. S to raziskavo smo pokazali, da je možno uporabiti naravne vire, jih modificirati in uporabiti za sintezo poroznih polimerov. V zadnji raziskavi smo se osredotočili na uporabo komercialno dostopnih naravnih spojin (terpenov) za sintezo naravnih poliHIPE materialov. Za sintezo teh materialov smo uporabili terpene limonen, karvon in mircen, ki smo jih zamrežili z multifunkcinalnimi akrilati. S kopolimerizacijo terpenov in akrilatov smo uspešno pripravili poliHIPE materiale na osnovi terpenov, ki so imeli specifično površino do 300 m2/g Z raziskavami v disertaciji smo pokazali, da je možno pripraviti odprtoporozne poliHIPE kroglice s številnimi aplikacijami, hkrati pa smo predstavili tudi bolj trajnostne in naravne pristope k sintezi le-teh.
Secondary keywords:	HIPE materiali;poliHIPE materiali;multiple emulzije;funkcionalni poliHIPE materiali;naravni polimeri;terpeni;doktorske disertacije;
Type (COBISS):	Doctoral dissertation
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	XV, 115 str.
ID:	19885298