Piernik Magdalena, Woźniak Magdalena, Pinkowski Grzegorz, Szentner Kinga, Ratajczak Izabela, Krauss Andrzej
Department of Woodworking Machines and Fundamentals of Machine Design, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 38/42, 60-637 Poznań, Poland.
Department of Chemistry, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 75, 60-625 Poznań, Poland.
Materials (Basel). 2022 Aug 6;15(15):5425. doi: 10.3390/ma15155425.
The aim of this study was to assess the effect of the duration of heat treatment on changes in the color, as well as the chemical and mechanical properties of Scots pine sapwood. An important element of the research was to obtain the assumed temperature in the entire volume of samples. Quantitative changes in color and its components were recorded, while mechanical properties were determined in tests of compressive strength parallel and perpendicular to the grain, longitudinal tensile strength and modulus of elasticity and impact strength. The novelty of the research was to determine the above-mentioned parameters for twin samples with identical moisture contents. Chemical analyses were conducted on heat-treated wood that was subjected to heat treatment at 220 °C for a period from 1 to 8 h. Extension of the heat treatment duration resulted in the increasing darkening of the wood, as well as a further reduction in the impact strength and tensile strength parallel to the grain by approx. 40 and 50%, respectively, compared to the control wood, but also compared to heat-treated wood for a shorter treatment duration. The heat treatment of wood caused changes in the contents of the wood components, as well as the elemental composition in the heat-treated wood, compared to the control pine. The changes in the structure of the heat-treated wood were confirmed by the attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Observed quantitative changes in the main wood components, its structural changes, as well as wood decomposition and increased crystallinity of cellulose explain significant changes in both the mechanical properties and the color of heat-treated wood.
本研究的目的是评估热处理持续时间对苏格兰松边材颜色变化以及化学和力学性能的影响。研究的一个重要因素是在样品的整个体积中获得假定的温度。记录颜色及其成分的定量变化，同时在平行和垂直于纹理的抗压强度、纵向拉伸强度、弹性模量和冲击强度测试中测定力学性能。该研究的新颖之处在于确定具有相同含水量的双份样品的上述参数。对在220°C下进行1至8小时热处理的热处理木材进行了化学分析。与对照木材相比，热处理持续时间的延长导致木材颜色进一步变深，以及与纹理平行的冲击强度和拉伸强度分别进一步降低约40%和50%，而且与较短处理时间的热处理木材相比也是如此。与对照松木相比，木材的热处理导致木材成分含量以及热处理木材中的元素组成发生变化。衰减全反射傅里叶变换红外光谱（ATR-FTIR）证实了热处理木材结构的变化。观察到的主要木材成分的定量变化、其结构变化以及木材分解和纤维素结晶度增加解释了热处理木材力学性能和颜色的显著变化。
