diplomsko delo univerzitetnega študijskega programa I. stopnje
Nicole Blažević (Avtor), Peter Krajnc (Mentor), Muzafera Paljevac (Komentor)

Povzetek

V diplomski nalogi z naslovom Vpliv zamreženja porozne poli(akrilne kisline) na absorptivne lastnosti smo sintetizirali porozno poli(akrilno kislino). Za pridobivanje poroznih materialov obstaja več različnih tehnik, mi smo se posluževali polimerizacije kontinuirne faze emulzije z visokim deležem notranje faze (HIPE polimerizacija). Pri naši sintezi je vlogo monomera igrala akrilna kislina, kot zamreževalo pa smo uporabljali N,N ́-metilenbisakrilamid (MMBA). Za nastanek emulzije so nujno potrebni še iniciator, mi smo uporabljali amonijev persulfat (APS), surfaktant, mi smo uporabljali Triton X-405, ter redukcijsko sredstvo, mi smo uporabljali tetrametiletilendiamin (TEMED). Reakcija je potekala po verižni radikalski polimerizaciji. Emulzija, ki smo jo pripravili je bila tipa olja v vodi. Kot notranjo fazo smo uporabljali topilo toluen. Materiale pred karaterizacijo je bilo potrebno očistiti z ekstrakcijo v Soxhletovem aparatu, kjer smo odstranili notranjo fazo, pri tem pa smo uporabljali topilo metanol. Sintetizirali smo več različnih materialov in sicer pri enem nismo dodali vodne raztopine NaOH, pri ostalih treh pa smo spreminjali stopnjo zamreženosti, ki je varirala med 10 %, 25 % in 50 %. Po sintezi smo del materiala pustili v metanolu, del smo ga pa dali sušiti v vakuumski sušilnik. Nato smo opazovali sestavo in absorptivno zmogljivost za vodni medij. Absorptivno zmogljivost smo preverjali pri materialu, ki se ni sušil v vakuumskem sušilniku, in sicer v deionizirani vodi. Pri materialih, ki so se sušili v vakuumskem sušilniku smo preverjali absorptivno zmogljivost v destilirani vodi, 0.1 M raztopini NaOH in 0.1 M raztopini HCl. Ugotovili smo, da se materili, ki imajo višjo stopnjo zamreženosti slabše absorbirajo kot materiali z nižjo stopnjo zamreženosti. Na samo absorptivnost vpliva tudi prisotnost baze v sami sestavi. Če je prisotna baza, nastane material z nabito hidrofilno skupino COONa, ki ima dobre absorptivne zmogljivosti. Če pa ni prisotna baza, nastane porozni material s kislinsko skupino COOH, ki ima slabše absorptivne zmogljivosti.

Ključne besede

emulzija;zamreženost;absorptivne lastnosti;poli(akrilna kislina);diplomske naloge;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.11 - Diplomsko delo
Organizacija: UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik: [N. Blažević]
UDK: 66.081.2:544.773.3.022.75(043.2)
COBISS: 32462339 Povezava se bo odprla v novem oknu
Št. ogledov: 386
Št. prenosov: 83
Ocena: 0 (0 glasov)
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Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Influence of cross-linking degree of porous poly(acrylic acid) on absorptive characteristics
Sekundarni povzetek: In the diploma thesis entitled Influence of cross-linking degree of porous poly (acrylic acid) on absorptive characteristics, was synthesized porous poly (acrylic acid). There are several different techniques for obtaining porous materials, we used the polymerization of the continuous phase of the emulsion with a high proportion of the internal phase (HIPE polymerization). Acrylic acid played the role of monomer in our synthesis, and N, N'-methylenebisacrylamide (MMBA) was used as a crosslinker. There are some essential reagent that take part in the emulsion formation, those are: initiator, we used ammonium persulfate (APS), a surfactant, we used Triton X-405, and a reducing agent, we used tetramethylethylenediamine (TEMED). The reaction proceeded after chain radical polymerization. The emulsion that we prepared was the oil-in-water type. Toluene solvent was used as the internal phase. Prior to characterization, the materials had to be purified by extraction in a Soxhlet apparate, where the inner phase was removed using a methanol solvent. Several different materials were synthesized, in one case the material was without aqueous NaOH solution, and in the other three we changed the degree of crosslinking, which varied between 10 %, 25 % and 50 %. After synthesis, part of the material was left in methanol and part was taken to vacuum dryer. After we observed composition and absorptive capacity in water medium. The absorbent capacity was checked for material, which remained in methanol, in deionized water. For vacuum dried materials, we tested the absorbent capacity in deionized water, 0.1 M NaOH solution and 0.1 M HCl solution. We found that materials with a higher degree of crosslinking are less absorbed than materials with a lower degree of crosslinking. The absorptivity itself is also affected by the presence of the base in the composition of the synthesized materials. If a base is present, a material with a hydrophilic COONa group is formed which has good absorptive capacity. However, if a base is not present, a porous material with a COOH group is formed, which has poorer absorptive capacity.
Sekundarne ključne besede: cross-linkig;emulsion;absorptive characteristics;HIPE;poly(acrylic acid);
Vrsta dela (COBISS): Diplomsko delo/naloga
Komentar na gradivo: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Strani: VIII, 28 str.
ID: 11979977