Merjenje fizikalno-kemijskih in transportnih lastnosti sistema polimer/SCF

diplomsko delo univerzitetnega študijskega programa I. stopnje

Tina Kegl (Author), Željko Knez (Mentor), Maša Knez Hrnčič (Co-mentor)

Abstract

Vedno večje zahteve po zmanjšanju negativnega vpliva na okolje in povečanju kakovosti proizvodov vodijo do pospešenih raziskav na področju razvoja novih tehnologij. Med razmeroma nove tehnologije uvrščamo visokotlačne procese s superkritičnimi fluidi, ki veljajo za okolju prijazna, zelena topila. Diplomsko delo prikazuje študijo fizikalno-kemijskih in transportnih lastnosti sistemov polimer/SCF z namenom procesiranja polimerov pri optimalnih eksperimentalnih pogojih. Preučevane lastnosti sistemov PEG 600/CO2 in Brij52/CO2 pri tlakih od 0 bar do 300 bar in temperaturah 333 K in 353 K so gostota, površinska napetost, topnost in difuzijski koeficient. Gostota sistema je določena z gostotomerom z nihajočo U-cevko in z magnetno suspenzijsko tehtnico. Površinska napetost je določena z metodo kapilarnega dviga. Magnetna suspenzijska tehtnica je bila uporabljena tudi za določanje difuzijskega koeficienta in topnosti superkritičnega CO2 v izbranih polimerih. Na osnovi analize eksperimentalno dobljenih fizikalno-kemijskih in transportnih lastnosti so določeni optimalni procesni parametri za procesiranje polimerov. Mikronizacija s superkritičnim CO2 polimera Brij52 in polimera Brij52 z zdravilno učinkovino esomeprazol je izvedena s PGSS-metodo, medtem ko je za pridobivanje polimerne pene iz Brij52 s superkritičnim CO2 uporabljena GF-metoda. V okviru diplomske naloge je izvedena tudi analiza dobljenih vzorcev po procesiranju polimerov z okoljskim vrstičnim elektronskim mikroskopom. Rezultati kažejo, da večjo topnost CO2 v talini polimera, večji difuzijski koeficient in manjšo površinsko napetost zagotavlja sistem Brij52/CO2 za vse izbrane tlake in temperature. Tlak in temperatura v avtoklavu pri mikronizaciji polimera Brij52 in polimera Brij52 z esomeprazolom ter tvorbi pene iz polimera Brij52 znašata 333 K in 150 bar. Po primerjavi dobljenih rezultatov sistema PEG 600/CO2 z razpoložljivimi rezultati iz literature ugotavljamo, da se vplivi posameznih preučevanih parametrov na fizikalno-kemijske in transportne lastnosti dobro ujemajo. Na osnovi tega lahko sklepamo, da so meritve uspešno izvedene tudi za sistem Brij52/CO2, za katerega ni ustreznih rezultatov v razpoložljivi literaturi.

Keywords

procesiranje polimerov;superkritični fluidi;gostota;površinska napetost;topnost;difuzijski koeficient;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2016
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[T. Kegl]
UDC:	532.612:54-139(043.2)
COBISS:	20342038
Views:	2409
Downloads:	1262
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	MEASUREMENT OF PHYSICAL-CHEMICAL AND TRANSPORT PROPERTIES OF THE POLYMER/SCF SYSTEM
Secondary abstract:	Ever increasing demands to reduce the negative impact on environment and to increase the quality of products lead to rising research activities in the development of new technologies. High pressure processes with supercritical fluids, which are considered to be environment friendly solvents, belong to relatively new technologies. This work focuses on a research of physical-chemical and transport properties of the polymer/SCF systems with the aim of polymer processing at optimal experimental conditions. The studied properties of the systems PEG 600/CO2 and Brij52/CO2 in a pressures range from 0 bar to 300 bar are as follows: density, interfacial tension, solubility, and diffusion coefficient. Density is determined by the density meter with a U-tube and with a Magnetic suspension balance. Interfacial tension is determined by the capillary rise method. The Magnetic suspension balance is also used to determine diffusion coefficient and solubility of supercritical CO2 in some chosen polymers. Based on the analysis of experimentally obtained physical-chemical and transport properties, optimal parameters for polymer processing are determined. Micronization of the polymer Brij52 without/with a medical substance esomeprazole was conducted by using the PGSS method with the supercritical CO2. On the other hand, the polymer foam from Brij52 by using supercritical CO2 was obtained by the GF method. In the scope of this work, the samples obtained after processing were analyzed, using an environmental scanning electron microscopy. The results show that higher CO2 solubility in a polymer melt, higher diffusion coefficient, and lower interfacial tension are obtained by using the Brij52/CO2 system for all examined pressures and temperatures. In that way the pressure and the temperature inside the autoclave were 150 bar and 333 K, respectively, during the micronization of polymers Brij52 and Brij52 with esomeparazole as well as during foam formation from the polymer Brij52. After comparing the obtained results from the system PEG 600/CO2 with the results available from the literature, it can be established that the influence of individual studied parameters on the physical-chemical and transport properties are consistent. Based on this, it can be concluded that the parallel measurements for the system Brij52/CO2 are also relevant, although such results are not available from the literature and no verification comparison could be carried out.
Secondary keywords:	polymer processing;supercritical fluids;density;interfacial tension;solubility;diffusion coefficient;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	XII, 85 str.
ID:	9160789