Chemical Composition as Factor Affecting the Mechanical Properties of Thermally Modified Black Poplar (Populus nigra L.)

Paweł Kozakiewicz, Michał Drożdżek, Agnieszka Laskowska, Marek Grześkiewicz, Olga Bytner, Andrzej Radomski, Agnieszka Mróz, Izabela Betlej, Janusz Zawadzki


Black poplar (Populus nigra L.) was thermally modified in superheated steam at 160 °C, 190 °C and 220 °C for 2 h. The research permitted to identify correlations between the chemical composition and selected mechanical properties of thermally modified wood. It has been demonstrated that higher treatment temperatures significantly lower the modulus of rupture (MOR), as well as Brinell hardness (BH). These correlations are particularly visible in higher temperatures (190 °C and 220 °C), when thermally modified wood undergoes a stronger hemicelluloses degradation, which manifests itself, among others, by an increase in the content of non-structural substances. Such wood properties like compressive strength parallel to the grain (CS) and modulus of elasticity during bending (MOE) and compressing (MCS) are less affected by the chemical changes caused by thermal processing of wood. Moreover, the level of wood moisture content also affects these changes.


Chemical composition; Compressive Strength; Hardness; Modulus of Rupture; Poplar; Thermal modification

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Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126