Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
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Chemical and Structural Characterization of Poplar and Black Pine Wood Exposed to Short Thermal Modification ; Kemijska i strukturna obilježja drva topole i crnog bora izloženih kratkotrajnoj toplinskoj modifikaciji
In this study, poplar and black pine wood was exposed to short thermal treatments, aiming to improve some crucial properties. Using wet chemical analyses and Fourier-transform infrared spectroscopy (FT-IR), the influence of these treatments on the chemical composition of the modified species was investigated, as well as on the wood structure, using scanning electron microscopy. With the increase of heat treatment intensity, a mass loss of both species was recorded, attributed to the moisture loss and degradation of volatile compounds, as well as thermally less stable components. In the first treatment stages, the extractives presented a decrease, whereas with the duration and temperature increase, new extractives were formed. Lignin increased its network through ramification, especially at 200 ºC, while holocellulose was found lower in all modified wood categories of both species than in unmodified wood due to the intense decomposition of hemicelluloses. The findings of FT-IR analyses were in line with the chemical analysis results. The thermal modification process made wood materials more hydrophobic and dimensionally stable, providing protection against decomposing factors. At the same time, they were not intensively thermo-degraded, which increased their utilization perspectives and application range as solid wood of enhanced properties, or as wood particles/fibers participating as raw materials in wood-based composite products, wood-polymers composites etc., enhancing their materials compatibility, properties and performance. ; U radu se opisuje istraživanje izlaganja drva topole i crnog bora kratkotrajnim toplinskim tretmanima radi poboljšanja nekih njihovih ključnih svojstava. Utjecaj tih postupaka na kemijski sastav modificiranih vrsta drva istražen je primjenom mokre kemijske analize i Fourierove transformirane infracrvene spektroskopije (FT-IR), a utjecaj na strukturu drva određen je uz pomoć pretražnoga elektronskog mikroskopa. Povećanjem intenziteta toplinskog tretmana zabilježen je gubitak mase obiju vrsta drva koji je pripisan gubitku vode te razgradnji hlapljivih i toplinski nestabilnih spojeva. U prvim fazama tretmana smanjio se udio ekstraktiva, dok su se s produljenjem tretmana i povećanjem temperature stvarali novi ekstraktivi. Lignin je povećao svoju umreženost razgranjivanjem, posebno na 200 °C, dok je udio holoceluloze bio manji u modificiranome nego u nemodificiranom drvu, i to zbog intenzivnog razlaganja hemiceluloze. Rezultati FT-IR analize u skladu su s rezultatima kemijske analize. Postupkom toplinske modifikacije drvo je postalo hidrofobnije, dimenzijski stabilnije i zaštićeno od čimbenika razgradnje, ali istodobno nije odviše toplinski razgrađeno, čime su se povećale mogućnosti njegove uporabe i proširila područja primjene kao masivnog drva poboljšanih svojstava ili kao sirovine za kompozitne materijale koja pridonosi njihovoj boljoj kompatibilnosti, svojstvima i performansama.
Chemical and Structural Characterization of Poplar and Black Pine Wood Exposed to Short Thermal Modification ; Kemijska i strukturna obilježja drva topole i crnog bora izloženih kratkotrajnoj toplinskoj modifikaciji
In this study, poplar and black pine wood was exposed to short thermal treatments, aiming to improve some crucial properties. Using wet chemical analyses and Fourier-transform infrared spectroscopy (FT-IR), the influence of these treatments on the chemical composition of the modified species was investigated, as well as on the wood structure, using scanning electron microscopy. With the increase of heat treatment intensity, a mass loss of both species was recorded, attributed to the moisture loss and degradation of volatile compounds, as well as thermally less stable components. In the first treatment stages, the extractives presented a decrease, whereas with the duration and temperature increase, new extractives were formed. Lignin increased its network through ramification, especially at 200 ºC, while holocellulose was found lower in all modified wood categories of both species than in unmodified wood due to the intense decomposition of hemicelluloses. The findings of FT-IR analyses were in line with the chemical analysis results. The thermal modification process made wood materials more hydrophobic and dimensionally stable, providing protection against decomposing factors. At the same time, they were not intensively thermo-degraded, which increased their utilization perspectives and application range as solid wood of enhanced properties, or as wood particles/fibers participating as raw materials in wood-based composite products, wood-polymers composites etc., enhancing their materials compatibility, properties and performance. ; U radu se opisuje istraživanje izlaganja drva topole i crnog bora kratkotrajnim toplinskim tretmanima radi poboljšanja nekih njihovih ključnih svojstava. Utjecaj tih postupaka na kemijski sastav modificiranih vrsta drva istražen je primjenom mokre kemijske analize i Fourierove transformirane infracrvene spektroskopije (FT-IR), a utjecaj na strukturu drva određen je uz pomoć pretražnoga elektronskog mikroskopa. Povećanjem intenziteta toplinskog tretmana zabilježen je gubitak mase obiju vrsta drva koji je pripisan gubitku vode te razgradnji hlapljivih i toplinski nestabilnih spojeva. U prvim fazama tretmana smanjio se udio ekstraktiva, dok su se s produljenjem tretmana i povećanjem temperature stvarali novi ekstraktivi. Lignin je povećao svoju umreženost razgranjivanjem, posebno na 200 °C, dok je udio holoceluloze bio manji u modificiranome nego u nemodificiranom drvu, i to zbog intenzivnog razlaganja hemiceluloze. Rezultati FT-IR analize u skladu su s rezultatima kemijske analize. Postupkom toplinske modifikacije drvo je postalo hidrofobnije, dimenzijski stabilnije i zaštićeno od čimbenika razgradnje, ali istodobno nije odviše toplinski razgrađeno, čime su se povećale mogućnosti njegove uporabe i proširila područja primjene kao masivnog drva poboljšanih svojstava ili kao sirovine za kompozitne materijale koja pridonosi njihovoj boljoj kompatibilnosti, svojstvima i performansama.
Chemical and Structural Characterization of Poplar and Black Pine Wood Exposed to Short Thermal Modification ; Kemijska i strukturna obilježja drva topole i crnog bora izloženih kratkotrajnoj toplinskoj modifikaciji
Kamperidou, Vasiliki (Autor:in)
01.01.2021
Drvna industrija : Znanstveni časopis za pitanja drvne tehnologije ; ISSN 0012-6772 (Print) ; ISSN 1847-1153 (Online) ; Volume 72 ; Issue 2
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
lignin , toplinski tretman , wood , kemijski sastav , drvo , thermal treatment , FT-IR , celuloza , chemical composition , FTIR , cellulose
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