Priprava poroznih polimerov s solvotermalno sintezo

diplomsko delo univerzitetnega študijskega programa I. stopnje

Nejc Donko (Author), Peter Krajnc (Mentor), Muzafera Paljevac (Co-mentor)

Abstract

V okviru diplomske naloge smo preučili vpliv polimerizacijskih pogojev, kot so uporaba različnih monomerov, temperatura avtoklaviranja in razmerje porogena in destilirane vode, na pripravo poroznih polimernih materialov s solvotermalno sintezo. Preučili smo vpliv zgoraj omenjenih polimerizacijskih pogojev na morfologijo polimernih materialov. Solvotermalno sintezo poroznih polimerov smo izvedli tako, da smo k monomeru in zamreževalu dodali ustrezno porogeno topilo in iniciator ter reakcijsko zmes mešali v dušikovi atmosferi. Samo polimerizacijo smo nato izvedli v avtoklavu, inducirali pa smo jo s povišanjem temperature, čemur je sledilo spontano povišanje tlaka v avtoklavu. Kot zamreževalo smo uporabili divinilbenzen in etilenglikol dimetakrilat, kot monomer pa stiren, glicidil metakrilat in 2-etilheksil akrilat. Tetrahidrofuran je bil uporabljen kot porogen. Pripraviti smo želeli monolit z visoko poroznostjo, malimi porami in visoko specifično površino. V ta namen smo spreminjali delež med monomerom in zamreževalom. Spreminjali pa smo tudi delež vode, za uravnavanje topnosti porogenega topila. Najprej smo monolit sintetizirali samo iz divinilbenzena, nato pa smo mu v različnih razmerjih dodali še stiren in 2-etilheksil akrilat. Z dodatkom različnih razmerij stirena in 2-etilheksil akrilata, smo želeli povečati elastičnost monolita. V nadaljevanju smo kot zamreževalo uporabili etilenglikol dimetakrilat, h kateremu smo dodali funkcionalni polimer glicidil matakrilat in pa tudi 2-etilheksil akrilat. Kot radikalski iniciator smo uporabili α,α'-azobisizobutironitril. Zmes porogena, vode, zamreževala, monomerov in iniciatorja smo mešali v stekleni bučki pri sobni temperaturi in nato prelili v stekleno posodico s pokrovom, odpornim na povišano temperaturo in pritisk. Avtoklavirali smo dva dni pri povišani temperaturi, s čimer smo sprožili polimerizacijo. Razpon temperature avtoklaviranja je bil od 80 pa do 100 °C. Nastale polimerne monolite smo očistili z etanolom v Soxhletu. Z analizo adsorpcije dušika po BET metodi smo jim določili specifično površino, celotni volumen in povprečni premer por. S Furier transform infrared (FTIR) spektroskopijo smo preverili kemijsko strukturo nastalih polimerov, morfologijo monolitnega materiala pa smo določili z vrstično elektronsko mikroskopijo, SEM. Ko smo avtoklavirali pri temperaturi 80 in 85 °C, nam produkt ni spolimeriziral v celoti. Volumski delež zamreževala in monomerov, ki nam je dal najboljše rezultate specifične površine, visoke poroznosti in malih por, je bilo 16,17 % divinilbenzena, 4,67 % stirena in 2,4 % 2-etilheksil akrilata, avtoklaviranje pa je potekalo pri 90 °C.

Keywords

polimeri;porozni polimeri;radikalna polimerizacija;solvotermalna sinteza;

Data

Language:	Slovenian
Year of publishing:	2015
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[N. Donko]
UDC:	665.652.2(043.2)
COBISS:	19425814
Views:	1369
Downloads:	112
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Preparation of porous polymers with solvothermal synthesis.
Secondary abstract:	This graduation thesis presents the effect of polymerization conditions, such as the use of different monomers, autoclaving temperature and the ratio of porogen and distilled water, in the preparation of porous polymeric materials with solvothermal synthesis. We have studied the impact of the above-mentioned polymerization conditions on the morphology of polymer materials. Solvothermal synthesis was preformed by mixing monomer, crosslinker, appropriate porogen, and an initiator. We then stireded the solution in nitrogen atmosphere. Polymerization was performed in an autoclave, and activated with elevated temperature, which was followed by spontaneous increase in pressure in an autoclave. As crosslinker divinylbenzene and ethylene glycol dimethacrylate was used, styrene, glycidyl methacrylate and 2-ethylhexyl acrylate was used as monomere. Tetrahydrofuran was used as porogen. We wanted to prepare a monolith with high porosity, small pore size and high specific surface area. To this end were changing share of monomer and crosslinker. We were also changing the proportion of distilled water, to regulate the solubility of the porogen solvent. First we synthesized a monolith only of divinylbenzene, then we added monomer styrene. With the addition of 2-ethylhexyl acrylate, we wanted to increase the elasticity of the monolith. In the following we used ethylene glycol dimethacrylate as crosslinker, to which functional polymer glycidyl matakrilat was added and also 2-ethylhexyl acrylate, and their ratio was changed. We used azobisisobutyronitrile as a radical initiator. We stirred a mixture of porogen, water, crosslinker, monomers and initiator in a glass flask at room temperature and then poured it into a glass container with a lid that is resistant to elevated temperature and pressure. We autoclaved for two days at an elevated temperature, thus polymerization was initiated. Autoclaving temperature range was from 80 up to 100 °C. Synthesized polymer monoliths were cleaned in Soxhlet with ethanol. By nitrogen adsorption analysis according to BET method, we have determined the specific surface area, total pore volume and the average pore diameter. Chemical structure of synthesized polymers was checked with FTIR spectroscopy. The morphology of monolithic material was determined by high resolution scanning electron micrograph, SEM. When we avtoclaved at a temperature of 80 and 85 °C, product was not fully polymerized. Volume share of crosslinker and monomers, which has provided us with the best results of the specific surface area, high porosity and small pore size was 16.17 % of divinylbenzene, 4.67 % of styrene, and 2.4 % of 2-ethylhexyl acrylate. Autoclaving was carried out at 90 °C.
Secondary keywords:	polymers;porous polymers;radical polymerization;solvothermal synthesis;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	64 str.
ID:	8888665