diplomsko delo
Lucija Strle (Author), Romana Cerc Korošec (Mentor)

Abstract

Postopek toplotne modifikacije uporabljamo, da lesu izboljšamo njegove lastnosti, kot so manjša higroskopnost, boljša dimenzijska stabilnost ter večja odpornost proti lesnim škodljivcem. Zaradi velike razširjenosti hrastovega lesa v Sloveniji sem se v okviru diplomskega dela ukvarjala z določitvijo stopnje toplotne modifikacije te lesne vrste. Vzorce hrastovega lesa smo modificirali v odsotnosti kisika pri temperaturah 170 °C, 180 °C, 190 °C, 200 °C, 205 °C in 210 °C. Ti vzorci so nam predstavljali standardne vzorce, saj smo iz razlike mase pred in po toplotni modifikaciji enostavno določili izgubo mase med tem procesom. Po modifikaciji smo toplotno obdelane vzorce analizirali s termogravimetrijo v temperaturnem območju med 25 °C in 600 °C v pretoku dušika ter iz podatkov izdelali umeritvene krivulje, ki so prikazovale izgubo mase pri TG meritvi v odvisnosti od izgube mase med toplotno modifikacijo. Skoraj vse umeritvene krivulje so odražale linearno odvisnost. Najvišji korelacijski koeficient je imela umeritvena krivulja v območju med 130 °C in 280 °C, sledila ji je umeritvena krivulja v območju med 130 °C in 290 °C, nato umeritvena krivulja v območju med 130 °C in 300 °C in zadnja, z najnižjim korelacijskim koeficientom, katere odvisnost tudi ni bila linearna, umeritvena krivulja v območju med 25 °C in 130 °C. Izdelane umeritvene krivulje lahko uporabljamo za določitev izgube mase med toplotno modifikacijo neznanih vzorcev.

Keywords

hrastov les;toplotna modifikacija;kemijske spremembe lesa;fizikalne spremembe lesa;stopnja toplotne modifikacije;termična analiza;termogravimetrija;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [L. Strle]
UDC: 674:543.573(043.2)
COBISS: 75533059 Link will open in a new window
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Downloads: 40
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Other data

Secondary language: English
Secondary title: Thermal modification of oak wood and determination of its degree using thermogravimetry
Secondary abstract: The process of thermal modification is used to improve wood properties such as lower hygroscopicity, better dimensional stability and increased resistance to pests. Due to the high prevalence of oak wood in Slovenia, my diploma work focuses on determining the degree of thermal modification of this wood species. Oak wood samples were modified at temperatures of 170 °C, 180 °C, 190 °C, 200 °C, 205 °C and 210 °C in the absence of oxygen. These samples represented standard samples, as we simply determined the mass loss during this process from the difference in mass before and after thermal modification. After modification, the heat-treated samples were analysed by thermogravimetry in the temperature range between 25 °C and 600 ° C in a nitrogen flow. Calibration curves were prepared from the obtained data. They represent the mass loss during TG measurement as a function of the mass loss during thermal modification. Almost all calibration curves showed a linear dependence. The highest correlation coefficient was obtained from the calibration curve in the range between 130 °C and 280 °C, followed by the calibration curve in the range between 130 °C and 290 °C, and the calibration curve in the range between 130 °C and 300 °C. The lowest correlation coefficient was obtained in the range between 25 °C and 130 °C; this dependence was also non-linear. The prepared calibration curves can be used to determine the mass loss during thermal modification of unknown samples.
Secondary keywords: thermal modification;oak wood;thermogravimetric analysis;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000374
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages: VII, 35 str.
ID: 13296256