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Izpis gradiva

Naslov:SINTEZA POLI(STIREN-DIVINILBENZEN) ZRN IZ SUSPENZIJE IN OPTIMIZACIJA SPECIFIČNE POVRŠINE
Avtorji:Zore, Žan (Avtor)
Krajnc, Peter (Mentor) Več o mentorju... Novo okno
Datoteke:.pdf UNI_Zore_Zan_2014.pdf (7,83 MB)
 
Jezik:Slovenski jezik
Vrsta gradiva:Diplomsko delo (m5)
Tipologija:2.11 - Diplomsko delo
Organizacija:FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Opis:V diplomskem delu je predstavljen vpliv raznih parametrov na poroznost, velikost in velikostno porazdelitev poli(stiren-divinilbenzen) zrn. Uporabili smo monomere stiren, divinilbenzen in 2-etilheksilakrilat. Za primerjavo smo pripravili še zrna iz monomerov etilenglikol dimetakrilata in glicidil metakrilata. Divinilbenzen in etilenglikol dimetakrilat sta služila kot zamreževalo, 2-etilheksilakrilat pa kot monomerni plastifikator. Z namenom študije polimernih zrn smo spreminjali porogeno topilo in njegovo količino, količino zamreževala, hitrost mešanja in obliko reaktorja. Pripravljena zrna smo okarakterizirali z optičnim mikroskopom pri 40-kratni povečavi in z adsorbcijsko/desorpcijsko porozometrijo z BET metodo izmerili specifično površino nastalih polimernih zrn. Kot porogen smo uporabili dobra in slaba topila ter linearni polimer. Dobra topila so bila toluen, tetrahidrofuran in klorobenzen, slaba topila n-heptan in izopropanol ter kot polimerni porogen polistiren raztopljen v toluenu ali klorobenzenu. Največjo specifično površino smo zasledili pri uporabi n-heptana. Do iste ugotovitve smo prišli pri uporabi n-heptana pri zrnih iz monomerov etilenglikol dimetakrilata in glicidil metakrilata. Ta zrna v primerjavi s poli(stiren-divinilbenzen) zrni niso bila pravilne okrogle oblike. S povečevanjem volumskega deleža porogena se je povečevala tudi poroznost, vendar se je pri vzorcih z več kot 50 % deležem začela zmanjševati, kar je posledica sesedanja por. Da bi preprečili sesedanje por, smo dodali plastifikator 2-etilheksilakrilat za povečanje mehanske trdnosti. Pri vplivu povečevanja deleža zamreževala smo ugotovili povečanje specifične površine, vendar smo s tem izgubljali delež monomera. Prav tako smo proučevali vpliv hitrosti mešanja; ugotovili smo, da se velikost povprečnih premerov zrn s povečevanjem hitrosti mešala zmanjšuje. Opazili smo tudi nekaj odstopanj v območju zelo nizkih in zelo visokih vrtljajev mešala. Pri spremembi oblike reaktorja iz takšnega z zaobljenim dnom na okroglo reaktorsko bučko smo opazili povečanje premera zrn. Naredili smo tudi zrna s kombinacijo spreminjanja zgoraj naštetih parametrov z željo po čim večji poroznosti zrn.
Ključne besede:polimeri, suspenzijska polimerizacija, polimerni delci, poroznost, stiren, divinilbenzen, velikost zrn
Leto izida:2013
Založnik:[Ž. Zore]
Izvor:Maribor
UDK:66.095.26(043.2)
COBISS_ID:17695254 Povezava se odpre v novem oknu
NUK URN:URN:SI:UM:DK:BSXNVKBI
Število ogledov:1515
Število prenosov:157
Metapodatki:XML RDF-CHPDL DC-XML DC-RDF
Področja:KTFMB - FKKT
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Sekundarni jezik

Jezik:Angleški jezik
Naslov:SYNTHESIS OF POLY(STYRENE-DIVINYLBENZENE) BEADS FROM SUSPENSION AND OPTIMIZATION OF SPECIFIC SURFACE AREA
Opis:The thesis discusses the influence of various parameters on the porosity, size and size distribution of poly(styrene-divinylbenzene) beads. The monomers that have been used were styrene, divinylbenzene and 2-ethylhexylacrylate. Beads from monomers ethylene glycoldimethacrylate and glycidylmethacrylate have been prepared in order to compare them to styrene-divinylbenzene ones. Divinylbenzene and ethylene glycoldimethacrylate serve as crosslinkers and 2-ethylhexylacrylate serves as monomer plasticiser. In order to study the properties of polymer beads, porogen and its quantity, the quantity of crosslinkers, the stirring rate and the shape of the reactor have been varied. Prepared particles have been characterized using an optical microscope at 40-fold magnification and with the adsorption/desorption porosimetry, where BET method has been used to determine the specific surface area of created polymer beads. As the porogen, we used a good solvent, a bad solvent and a linear polymer porogen. Good solvents were toluene, tetrahydrofuran and chlorobenzene. Bad solvents were n-heptane and isopropanol and as a polymeric porogen polystyrene dissolved in toluene or chlorobenzene has been used. The highest specific surface area of poly(styrene-divinylbenzene) beads and poly(glycoldimethacrylate-glycidylmethacrylate) beads was observed when n-heptane was used. It has been noticed that poly(glycoldimethacrylate-glycidylmethacrylate) beads were irregularly shaped, whereas poly(styrene-divinylbenzene) beads were spherically shaped. With the increasing volume of porogen the porosity increased, but it decreased with the samples that had more than 50 vol% of porogen. We concluded that the decrease in porosity happened as a result of collapsing pores. In order to prevent further collapsing, 2-ethylhexylacrylate as a plasticizer was added to improve the mechanical strength of the material. When the amount of crosslinkers was increased, the resulting polymer had higher surface area, but because of that the quantity of monomer diminished. We have also studied the influence of stirring rate, where we came to the conclusion that the average size of beads decreases with the increasing stirring rate. We also observed some deviations in the range of very low or very high stirring rates. When changing pear-shaped flask with round-bottomed flask we noticed an increase in bead diameter. We also prepared beads by using a combination of various parameters, described above, with the desire to maximize the surface area of the particles.
Ključne besede:polymers, suspension polymerization, particle polymers, porosity, styrene, divinylbenzene, bead size


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