Bytner Olga, Drożdżek Michał, Laskowska Agnieszka, Zawadzki Janusz
The Institute of Wood Sciences and Furniture, 159 Nowoursynowska St., 02-776 Warsaw, Poland.
Materials (Basel). 2022 Nov 10;15(22):7949. doi: 10.3390/ma15227949.
The thermal modification of wood in a nitrogen atmosphere shapes the functional properties of wood. The aim of this research was to determine the influence of different levels of temperature and the duration of thermal modification on the mechanical properties of the black poplar ( L.). Black poplar was thermally modified in nitrogen atmosphere in the temperature range from 160 °C to 220 °C (6 levels) for 2 h to 8 h (4 levels), resulting in a total of 24 treatments. The effect of these treatments on compressive strength parallel to the grain (CS), modulus of rupture (MOR), and modulus of elasticity during bending (MOE) were analyzed. Thermal modification influenced the mechanical properties of black poplar wood. After thermal modification occurred in a nitrogen atmosphere, an increase in compressive strength was noticeable for all variants of black poplar wood modification. The highest 16% increase in CS was obtained for the modification carried out at the temperature of 160 °C and for 2 h. An increase was also found for MOE when modified under mild conditions, while a decrease occurred for variants at higher temperatures, i.e., for 200 °C and 220 °C. The study showed that for all modification variants, there was a decrease in MOR alongside the increase in modification temperature and time.
在氮气气氛中对木材进行热改性可塑造木材的功能特性。本研究的目的是确定不同温度水平和热改性持续时间对黑杨（L.）力学性能的影响。将黑杨在氮气气氛中于160℃至220℃（6个水平）的温度范围内进行2小时至8小时（4个水平）的热改性，共得到24种处理。分析了这些处理对顺纹抗压强度（CS）、抗弯强度（MOR）和抗弯弹性模量（MOE）的影响。热改性影响了黑杨木材的力学性能。在氮气气氛中进行热改性后，所有黑杨木材改性变体的抗压强度均显著提高。在160℃温度下进行2小时的改性，CS提高幅度最大，达16%。在温和条件下改性时MOE也有所增加，而在较高温度（即200℃和220℃）下的变体则出现下降。研究表明，对于所有改性变体，随着改性温度和时间的增加，MOR均有所下降。
