doktorska disertacija
Irena Pulko (Author), Peter Krajnc (Mentor), Aleš Podgornik (Co-mentor)

Abstract

V okviru doktorske disertacije smo proučili vpliv pogojev na pripravo akrilatnih ter vinibenzil kloridnih tipov poroznih netopnih polimernih nosilcev. Proučili smo vpliv polimerizacijskih pogojev na supramolekularno strukturo in morfologijo ter reaktivnost polimernih nosilcev. Nove polimerne nosilce v monolitni, zrnati in membranski obliki smo uporabili pri procesih separacij in čiščenja ter pri procesih katalize. Aktiven polimerni nosilec, primeren za nadaljnje vezave in funkcionalizacije lahko pripravimo iz različnih monomerov, ki pa so pogosto dragi ali komercialno nedostopni. Zato smo v začetnem delu doktorata pripravili nosilce poli(akrilne kisline) in jih pretvorili v poli(akriloil klorid). Zaradi dobro izstopajoče kloridne skupine je možna enostavna funkcionalizacija. Proučili smo vpliv polimerizacijskih pogojev, stopnje zamreženja, dodatka porogena in komonomera ter vrste in količine stabilizatorja na omenjeno pretvorbo. Za uspešno aplikacijo je pomembna združljivost matrike in topila; običajno je matrika združljiva zgolj s polarnimi ali nepolarnimi topili. Zato smo se odločili, da v naslednji stopnji pripravimo matriko, ki bo združljiva s širokim spektrom topil. V ta namen smo pripravili zrnate in poliHIPE nosilce na osnovi vinilbenzil klorida in jih hiperzamrežili s Friedel-Craftsovo reakcijo. Med hiperzamreženjem se tvori fino porozna struktura, ki se obdrži tudi po odstranitvi topila. Polimer ima visoko specifično površino in je združljiv tako s termodinamsko ugodnimi kot neugodnimi topili. 4-metilaminopiridin smo kovalentno vezali na izhodne in hiperzamrežene nosilce ter spremljali katalitsko aktivnost imobiliziranega katalizatorja pri reakciji aciliranja in Baylis-Hillmanovi reakciji. Učinkovitost katalizatorja je močno odvisna od matrike, na katero je imobiliziran; hiperzamrežena matrika se je domala v vseh primerih izkazala kot učinkovitejša. Združljivost matrike in termodinamsko ugodnega ter neugodnega topila smo študirali z izvedbo reakcije v toluenu in dietiletru. Smotrnost imobilizacije katalizatorja smo potrdili z večkratno zaporedno uporabo imobiliziranega katalizatorja, brez bistvenega zmanjšanja učinkovitosti. Pri olefinsko metateznih reakcijah se pogosto uporabljajo katalizatorji tipa Grubbs, ki jih je potrebno po reakciji ločiti iz produktne mešanice. Zato smo pripravili nosilce na osnovi 4-nitrofenil akrilata, jih hidrolizirali, pretvorili v kislinski klorid in funkcionalizirali z 1,4-butandiolviniletrom, ter študirali vpliv morfologije in kemijske strukture nosilca na učinkovitost kovalentne vezave rutenijevega katalizatorja iz produktne mešanice. Nadalje smo študirali vpliv morfologije in kemijske strukture na odstanitev atrazina iz raztopine z nosilcem, funkcionaliziranim s piperazinom. Za odstranitev smo uporabili nosilca na osnovi 4-nitrofenil akrilata in 4-vinilbenzil klorida; slednjega smo pred funkcionalizacijo hiperzamrežili. Najučinkovitejši je bil hiperzamrežen nosilec, ki je atrazin odstranil v petnajstih minutah. Glede na to, da je aktivnost kazal tudi hiperzamrežen nefunkcionaliziran nosilec, predvidevamo da odstranitev ni posledica zgolj kovalentne vezave, ampak tudi adsorpcije. Z namenom uporabe membran v separacijske namene v obliki membranskih modulov smo pripravili zamrežene poliHIPE membrane na osnovi glicidil metakrilata. Študirali smo vpliv dodatka etilheksil akrilata, stopnje zamreženja in dodatka interne faze na njihovo morfologijo, pretočnost in mehanske lastnosti. Vezana kapaciteta proteina bovin serum albumin je znašala 45 mg/mL, kar je več kot v primerih analognih monolitnih nosilcev.

Keywords

polimeri;makroporozni polimeri;poliHIPE;emulzija;organski katalizatorji;monoliti;membrane;poliakrilati;poli(vinilbenzil klorid);

Data

Language: Slovenian
Year of publishing:
Source: [Maribor
Typology: 2.08 - Doctoral Dissertation
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: I. Pulko]
UDC: 678.744.32:544.725(043.3)
COBISS: 13169686 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Porous polyacrylates and poly(vinylbenzyl chloride) for immobilisation of organic compounds
Secondary abstract: Influences of reaction conditions and media on the preparation of macroporous crosslinked acrylate and vinylbenzyl chloride type polymer supports were studied. The focus of the work was on the relations between preparation conditions and supramolecular structure and morphology. Furthermore, chemical reactivity was studied in view of the preparation of specifically modified supports. Novel polymer supports with monolithic, membrane and particulate shape were applied in the processes of separation, purification and catalysis. Activated polymeric supports capable of further functionalisation can be prepared from different monomers, however they might be commercially inaccesible or expensive. As the first task therefore the preparation of polymeric supports from acrylic acid and functionalised to acid chloride was set. Immobilised acid chloride represents a very versatile support for various functionalisations and immobilizations of species. Influences of polymerisation conditions, porogen, comonomer additions and stabiliser were studied. For a successful application of a polymeric support the compatibility of polymer matrix with the solvent is very important and incompatibility can represent a significant drawback of the polymer support. Therefore one of the major goal was to investigate the preparation of porous polymer matrix compatible with both polar and non polar solvents. Hypercrosslinking technique by a Friedel-Crafts type reaction between chloromethyl groups in the polymer matrix was applied to achieve this, and to increase the surface area of the material at the same time. To this kind of novel material 4-methylaminopyridine was tethered covalently and applied as a heterogenuous catalyst for acylation reactions and for the Baylis-Hillman's reaction. It was found that the efficiency of the polymer bound catalyst depends strongly on the precursor matrix and the crosslinking degree. Furthermore, polymeric supports of 4-nitrophenyl acrylate type were used for the removal of Grubbs second generation type Ru catalysts from the reaction media during the metathesis polymerisation procedures. 1,4-butanediolvinylether functionalised polymers were used and the influence of the polymer matrix type studied. Specifically functionalised polymer support, namely piperazine functionalised, was applied for a procedure of removing atrazine in very low concentrations from aqueous solutions with an aim of covalent attachment of the triazine type pesticides. Here, too, the hypercrosslinking had a substantial influence on the kinetics of the pesticide removal and it was concluded that in the case of the hypercrosslinked polymer, both covalent attachment and adsorption took place. In the last part of the thesis work, the conditions for the preparation of polyHIPE type membranes were studied. Glycidyl methacrylate was chosen as the main functional monomer due to availability and possibility of nucleophilic modifications of epoxy groups. With an aim of preparing membranes with a through porous type cellular and highly interconnected morphology (polyHIPE membranes), influences of added ethylhexyl acrylate (plastisizer), crosslinking degree and the added internal phase of the emulsions on the properties and morphology of the membranes were studied. Membranes were applied for the separation of proteins and the binding capacity of 45 mg/mL for bovine serum albumine was found which exceeds comparable monolithic polymers currently on the market.
Secondary keywords: polymers;macroporous polymers;polyHIPE;emulsions;organic catalysts;monoliths;membranes;polyacrylates;poly(vinylbenzyl chloride);
URN: URN:SI:UM:
Type (COBISS): Dissertation
Thesis comment: Univ. Maribor, Fak. za kemijo in kemijsko tehnologijo
Pages: 166 str.
Keywords (UDC): applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;various industries;trades and crafts;razne industrije;obrti in rokodelstva;industries based on macromolecular materials;rubber industry;plastics industry;industrija makromolekulskih snovi;industrija kavčuka;industrija umetnih snovi;synthetic polymerization products;polymerizates;synthetic rubbers;sintetični polimerizacijski produkti;polimerizati;sintetični kavčuk;mathematics;natural sciences;naravoslovne vede;matematika;chemistry;crystallography;mineralogy;kemija;physical chemistry;fizikalna kemija;chemistry of surface phenomena and colloids;kemija površinskih pojavov in koloidov;
ID: 986185