Makroporozni polimeri iz 2-hidroksietil metakrilata

diplomsko delo univerzitetnega študijskega programa

Lara Terzić (Avtor), Peter Krajnc (Mentor), Muzafera Paljevac (Komentor)

Povzetek

V diplomskem delu smo na podlagi dveh različnih metod sintetizirali produkte, ki vsebujejo 2-hidroksietil metakrilat. Pripravili smo polimerne poliHIPE monolitne produkte iz emulzij tipa O/V in polimere PHEMA z uporabo sintranih delcev PMMA. Poli(2-hidroksietil metakrilat) (PHEMA) je hidrofilni in biokompatibilni polimer, ki se uporablja na primer kot material za kontaktne leče (hidrogel), za dostavo aktivnih učinkovin, 3D nosilec v tkivnem inženirstvu, idr. Za pridobivanje PHEME smo izvedli termično polimerizacijo in fotopolimerizacijo. Pri obeh metodah smo preučevali vpliv različnih dejavnikov kot so: volumski deleži posameznih faz, zamreževal, hitrost mešanja, temperatura ob mešanju emulzije, staranje emulzije, dodajanje aditivov, različen čas sintranja PMMA in različni načini sušenja monolitov. Cilj naloge je z različnimi eksperimentalnimi postopki ter s spreminjanjem različnih parametrov pridobiti morfološko najbolj primeren polimer, torej bimodalno porazdelitev por, kar pomeni, da so poleg že omenjenih makro por, prisotne tudi pore v nano dimenzijah, t.i. terciarne pore. V ta namen smo uporabili kombinacijo koloidnega sistema ob dodatku porogenih topil. Bimodalno razporeditev por in nekoliko večje vrednosti specifične površine, smo dosegli pri sintezi poliHIPE produktov z dodatkom 10 ut% porogenih topil, t.j. višjih (maščobnih) alkoholov. Na podlagi rezultatov študij vpliva deleža zamreževala in interne faze cikloheksana, smo ugotovili najugodnješo sestavo emulzije za nadaljne eksperimente in sicer 80 vol % cikloheksana ob souporabi 15 mol % zamreževala MBAA. V diplomskem delu je prikazana tudi analiza vpliva različne hitrosti mešanja emulzije na polimeriziran produkt, pri čemer produkt, sintetiziran iz emulzije, mešane pri 150 obr/min rezultira z bistveno večjimi porami kot tisti z mešanjem emulzije pri 300 obr/min. Pri sintezi polimerov s sintranjem PMMA, smo pridobili produkte s precej večjimi primarnimi porami (tudi do 100 µm), kot pri sintezi polHIPE produktov, vendar so poliHIPE produkti rezultirali s kompleksnejšo morfologijo, ki bi celicam omogočala boljši pretok hranilnih snovi in rast. Rezultati kažejo, da je fotopolimerizacija ugodnejša kot termična polimerizacija, saj je produkt z uporabo foto iniciatorja bolj homogene teksture in morfologije, pri čemer fotopolimerizacija poteče hitreje kot termična polimerizacija. Čas sintranja in velikost delcev PMMA je imel bistven vpliv na poroznost in morfologijo produktov, pri čemer smo ugotovili, da se pri 24 h sintranja delci bolje zlepijo in po odstranitvi matrice pridobimo makroporozen polimer. Diplomsko delo prikazuje študijo pridobivanja polimerov, ki bi potencialno lahko služili za nadaljne študije na področju biomedicine in ostalih ved.

Ključne besede

makroporozni polimeri;poroznost;monoliti;poliHIPE;PHEMA;

Podatki

Jezik:	Slovenski jezik
Leto izida:	2014
Tipologija:	2.11 - Diplomsko delo
Organizacija:	UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik:	[L. Terzić]
UDK:	54-126:547(043.2)
COBISS:	18298134
Št. ogledov:	1990
Št. prenosov:	178
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	MACROPOROUS POLYMERS FROM 2-HYDROXYETHYL METHACRYLATE
Sekundarni povzetek:	The thesis is based on two different methods of synthesizing products containing 2-hydroxyethyl methacrylate. The polymeric PolyHIPE monolithic products, from emulsion type O/V and PHEMA polymers with the use of sintered PMMA particles, have been prepared. Poly (2-hydroxyethyl methacrylate) (PHEMA) is hydrophilic and biocompatible polymer, which is used for example as a material for contact lenses (hydrogel), for the delivery of active ingredients, the 3D scaffold in tissue engineering, etc.To obtain PHEMA the thermal polymerization and fotopolimerisation are performed. For both methods, we studied the influence of various factors such as volume percentage of each phase, crosslinkers, stirring rate, temperature during stirring of emulsion, the emulsion aging, addition of additives, different time periods of sintering PMMA, different ways of drying the monoliths. The objective of the thesis is the study of different experimental procedures, and by changing the various parameters to obtain the most suitable polymer morphology, known as bimodal pore size distribution, which means that in addition to the above-mentioned macro-pores, pores in the nano-dimensions or so-called tertiary pores are also present in the skelet of the polyHIPE. To this end, we used a combination of the colloidal system with addition of porogenic solvents. Bimodal distribution of pores, and higher values of specific surface area, have been obtained by the synthesis of PolyHIPE products with the addition of 10 wt% porogenous solvents, namely higher (fatty) alcohols. Based on the results study of the influence of the proportion of crosslinker and internal phase of cyclohexane, we found the most efficient composition of emulsions for further experiments, that is 80 vol% of cyclohexane with 15 mol% MBAA of crosslinker. In the thesis it is shown also the analysis of the influence of different speeds of stirring the emulsion and it's effect on polymerized products, wherein the products synthesized from an emulsion, mixed at 150 rpm result in a substantially greater pore size than that one by mixing the emulsion at 300 rpm. In the synthesis of polymers by sintering PMMA, we obtain a significantly higher diameter values of primary pores (even up to 100 µm), than in the synthesis of polHIPE products, but PolyHIPE products resulted in a more complex morphology, that would allow better flow of nutrients and better cell growth. The results show that the photopolymerisation is more favorable than thermal polymerisation since the product obtained by using a photo initiator is more homogeneous in texture and morphology, because the reaction of photopolimerisation is faster than the thermal polymerization. The time of sintering and the particle size of the PMMA has had a substantial influence on the porosity and morphology of the products, we found that at 24 hours, sintered particles adhesed better. After removal of PMMA matrix the macro-porous polymer is obtained. The thesis presents a study about obtaining polymers, which could potentially serve to further studies in the field of biomedicine and other disciplines.
Sekundarne ključne besede:	macroporous polymers;porosity;monolits;polyHIPE;PHEMA;
URN:	URN:SI:UM:
Vrsta dela (COBISS):	Diplomsko delo
Komentar na gradivo:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Strani:	X, 63 str.
ID:	8730851