20.500.12556/DKUM-82529 Eksperimentalna raziskava rumenenja PVC diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje Experimental study of PVC yellowing Poli(vinil klorid) oz. PVC je enostaven polimer pripravljen iz vinilkloridnega monomera s prosto radikalsko polimerizacijo. Sinteza polimera ter njegovi materiali so relativno poceni. PVC ni možno samostojno obdelati zaradi njegove zelo nizke termične stabilnosti ter visoke viskoznosti. Zato je potrebno polimeru dodati številne dodatke, da dobimo širok in raznolik nabor lastnosti. Zaradi možnosti širokega nabora lastnosti je PVC-ju omogočena široka uporaba. PVC ima slabo toplotno in svetlobno stabilnost. Podvržen je hitremu avtokatalitskemu dehidrokloriranju. Odcepitev HCl od polimernega ogrodja slabo vpliva na njegove lastnosti. PVC-ju se zaradi tega dodajajo številni dodatki. Eden najpomembnejših dodatkov za PVC so polnila, ki so se včasih uporabljala zgolj z namenom znižanja stroškov. Dandanes imajo polnila različne funkcije, nepogrešljiva pa so postala predvsem mineralna polnila. Najpomembnejše in najbolj uporabljeno polnilo pri proizvodnji PVC-ja predstavlja kalcijev karbonat. Kalcijev karbonat se odlikuje kot polnilo predvsem zaradi svoje kemične čistosti, visoke beline, nizkega lomnega količnika ter nizke abrazivnosti. V diplomski nalogi smo preučevali, kako vpliva kalcijev karbonat na lastnosti PVC-ja. Za sintezo PVC profilov smo uporabili 9 različno pripravljenih oplaščenih kalcijevih karbonatov. Kalcijev karbonat smo prvo zmešali s PVC praškom ter stabilizatorjem, da smo pripravili suho mešanico, ki smo jo nato ekstrudirali. Nastalim PVC profilom smo izmerili stabilnost pri povišanih temperaturah ter izpostavljenosti UV svetlobi. Termično stabilnost smo določali z merjenjem optičnih lastnosti po določenem času izpostavljenosti visokim temperaturam ter s konduktometrično DHC analizo in analizo z DSC-jem. UV stabilnost smo pa spremljali s spremembo optičnih lastnosti po določenem času izpostavljenosti UV svetlobi. Poly (vinyl chloride) oz. PVC is a simple polymer prepared from vinyl chloride monomer by free radical polymerization. The synthesis of the polymer and its materials are relatively cheap. PVC cannot be synthesized on its own due to its very low thermal stability and high viscosity. It is, therefore, necessary to add a number of different additives to the polymer to obtain a wide and varied range of properties. Because of being able to choose a wide range of properties by varying the added additives PVC is widely used. PVC has poor thermal and light stability. It undergoes rapid autocatalytic dehydrochlorination. The separation of HCl from the polymer negatively affects its properties. This results in a number of additives being added to PVC. One of the most important additives for PVC are fillers, which used to be applied only to reduce costs. Nowadays, fillers have different functions, but mineral fillers have become indispensable. The most important and widely used filler in PVC production is calcium carbonate. Calcium carbonate is distinguished as a filler mainly because of its chemical purity, high whiteness, low refractive index and low abrasivity. In the thesis we investigated how calcium carbonate affects the properties of PVC. For the synthesis of PVC profiles, 9 differently prepared coated calcium carbonates were used. The calcium carbonate was first mixed with PVC powder and a stabilizer to produce a dry blend, which was then extruded. The resulting PVC profiles were measured for stability at elevated temperatures and UV light exposure. Thermal stability was determined by measuring optical properties after a certain amount of time being exposed to high temperatures as well as a conductometric DHC analysis and DSC analysis. The UV stability was monitored by the change of the PVC optical properties after a fixed amount of time of the UV light exposure. PVC kalcijev karbonat optične lastnosti stabilnost PVC degradacija PVC analiza PVC PVC calcium carbonate optical properties stability of PVC degradation of PVC analysis of PVC true true false [D. T. Hren] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2022-08-23 21:55:27 2022-09-16 13:36:22 2022-11-24 03:07:00 0000-00-00 00:00:00 2022 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (X, 52 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 678.743.2.01(043.2) 130593795 VS_Hren_David_Tian_2022.pdf VS_Hren_David_Tian_2022.pdf 1 D64EEBCA9371DCE812182FA290CAF227 55b32ff0eb4f6f00080bfbbf11f64499f58e1da26f98cde990b819cda30a761c 4f6cd281-3345-11ed-80b1-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=162509 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0