Lignin dimeric units are characterized by various inter-unit linkage types such as β-O-4, β-5, β-β, and β-1. Spirodienones are the native form of the β-1 structures, but the content in lignin has not been clarified. In this study, the ring-1-13C labeled coniferin was synthesized and administered to Ginkgo biloba shoots, obtaining ring-1 selectively labeled xylem samples. Enzymatically saccharified lignin (EL) samples were prepared from the xylem sample (400–600 µm distant region from the cambial zone), and solution-state quantitative 13C NMR and solid-state CP/MAS NMR measurements were conducted. Acetylated EL (ELAc) was also prepared from the xylem sample (600–800 µm distant region from the cambial zone), and solution-state quantitative 13C NMR and 1H–13C 2D NMR measurements were conducted. Difference spectra obtained by subtracting the unlabeled spectra from the ring-1 labeled spectra showed that the ring-1 was responsible for broad signals at 134 ppm and signals of the spirodienone structure at 56.11 ppm (in solid-state), 54.70 ppm (EL in solution-state), and 54.72 ppm (ELAc in solution-state). The ratio of spirodienone structure was evaluated as 0.68 % (EL) and 0.72 % (ELAc) by the solution-state quantitative 13C difference spectra, and 2.3 % (ELAc) by HSQC volume ratio of Cα′-H to G2-H.
{"title":"Quantitative analysis of the β-1 structure in lignin by administration of [ring-1-13C]coniferin","authors":"Shori Imamura, Masaki Hosokawa, Yasuyuki Matsushita, Dan Aoki, Kazuhiko Fukushima, Masato Katahira","doi":"10.1515/hf-2023-0100","DOIUrl":"https://doi.org/10.1515/hf-2023-0100","url":null,"abstract":"Lignin dimeric units are characterized by various inter-unit linkage types such as β-O-4, β-5, β-β, and β-1. Spirodienones are the native form of the β-1 structures, but the content in lignin has not been clarified. In this study, the ring-1-<jats:sup>13</jats:sup>C labeled coniferin was synthesized and administered to <jats:italic>Ginkgo biloba</jats:italic> shoots, obtaining ring-1 selectively labeled xylem samples. Enzymatically saccharified lignin (EL) samples were prepared from the xylem sample (400–600 µm distant region from the cambial zone), and solution-state quantitative <jats:sup>13</jats:sup>C NMR and solid-state CP/MAS NMR measurements were conducted. Acetylated EL (ELAc) was also prepared from the xylem sample (600–800 µm distant region from the cambial zone), and solution-state quantitative <jats:sup>13</jats:sup>C NMR and <jats:sup>1</jats:sup>H–<jats:sup>13</jats:sup>C 2D NMR measurements were conducted. Difference spectra obtained by subtracting the unlabeled spectra from the ring-1 labeled spectra showed that the ring-1 was responsible for broad signals at 134 ppm and signals of the spirodienone structure at 56.11 ppm (in solid-state), 54.70 ppm (EL in solution-state), and 54.72 ppm (ELAc in solution-state). The ratio of spirodienone structure was evaluated as 0.68 % (EL) and 0.72 % (ELAc) by the solution-state quantitative <jats:sup>13</jats:sup>C difference spectra, and 2.3 % (ELAc) by HSQC volume ratio of Cα′-H to G2-H.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139092140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wood wettability, the process of liquid interaction with wood surfaces, is influenced by wood surface chemistry, structure, ambient conditions, and temperature. Understanding how temperature impacts wood wettability is crucial for high-temperature manufacturing processes. In this study, the sessile drop method was employed to explore the dynamic wettability of Chinese fir wood using three different liquids (water, glycerol and polyvinyl acetate (PVAc)) across a range of temperatures (25, 40, 60 and 80 °C). By considering spreading, penetration and evaporation, we revealed that the dynamic wettability of Chinese fir was strongly dependent on temperature and the type of liquid. Temperature elevation enhances wettability, leading to reduced contact angles and increased penetration ratios. Water exhibited the highest wettability, followed by glycerol, with PVAc being the least wetting agent. Notably, after 180 s of wetting at 80 °C, the measured contact angles were 0° for water, 45° for glycerol, and 120° for PVAc. When accounting for evaporation, the penetration of water decreased from 57 % to 47 % (25 °C) and 100 % to 62 % (80 °C). The activation energies for the penetration of water and PVAc into Chinese fir exhibited variations, with values of 35.3 and 158.3 kJ/mol, respectively. These comprehensive wetting results, covering spreading, penetration and evaporation, provide valuable insights into wood–water and wood–adhesive interactions, particularly when exposed to high-temperature conditions.
{"title":"Effect of temperature on the dynamic wettability of Chinese fir wood: integrative consideration of surface spreading, penetration and evaporation","authors":"Xianfu Xiao, Kaiwen Chen, Hui Peng, Jianxiong Lyu, Tianyi Zhan","doi":"10.1515/hf-2023-0096","DOIUrl":"https://doi.org/10.1515/hf-2023-0096","url":null,"abstract":"Wood wettability, the process of liquid interaction with wood surfaces, is influenced by wood surface chemistry, structure, ambient conditions, and temperature. Understanding how temperature impacts wood wettability is crucial for high-temperature manufacturing processes. In this study, the sessile drop method was employed to explore the dynamic wettability of Chinese fir wood using three different liquids (water, glycerol and polyvinyl acetate (PVAc)) across a range of temperatures (25, 40, 60 and 80 °C). By considering spreading, penetration and evaporation, we revealed that the dynamic wettability of Chinese fir was strongly dependent on temperature and the type of liquid. Temperature elevation enhances wettability, leading to reduced contact angles and increased penetration ratios. Water exhibited the highest wettability, followed by glycerol, with PVAc being the least wetting agent. Notably, after 180 s of wetting at 80 °C, the measured contact angles were 0° for water, 45° for glycerol, and 120° for PVAc. When accounting for evaporation, the penetration of water decreased from 57 % to 47 % (25 °C) and 100 % to 62 % (80 °C). The activation energies for the penetration of water and PVAc into Chinese fir exhibited variations, with values of 35.3 and 158.3 kJ/mol, respectively. These comprehensive wetting results, covering spreading, penetration and evaporation, provide valuable insights into wood–water and wood–adhesive interactions, particularly when exposed to high-temperature conditions.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139066646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuxin Zhao, Luxi He, Jiayi Kang, Jingjing Gao, Guochen Huo, Kai Xu, Tinghuan Wang, Zhengbin He, Zhenyu Wang, Songlin Yi
Thermal treatment is an effective method for improving the dimensional stability of wood; however, it typically requires high temperatures. To achieve low-temperature heat treatment, this study employed wood samples impregnated with 10 % tannin acid (TA) and examined their changes in dimensional stability and chemical components after heat treatment at various initial moisture content levels. The results revealed that the TA-10 %-HT group exhibited enhanced dimensional stability. Specifically, both the tangential and radial moisture swelling decreased by 21.7 % and 11.8 %, respectively. FTIR and XRD analysis indicated that the presence of tannin acid catalytically facilitated the degradation of hemicellulose. Moreover, an increase in moisture content resulted in the ionization of TA, amplifying acidity and further affecting cellulose degradation. TGA demonstrated that TA impacted the thermal stability of heat-treated materials by lowering the initial decomposition temperature of wood components and increasing the residual weight of wood. Overall, pretreatment with TA impregnation and moisture content significantly improved the dimensional stability of Chinese fir wood and altered its chemical composition. This approach holds considerable potential for enhancing wood properties through a low-energy consumption method during the heat treatment process, expanding the practical application of wood.
热处理是提高木材尺寸稳定性的有效方法，但通常需要较高的温度。为了实现低温热处理，本研究采用了浸渍了 10 % 单宁酸（TA）的木材样本，并在不同初始含水率水平下考察了热处理后木材尺寸稳定性和化学成分的变化。结果显示，TA-10 %-HT 组的尺寸稳定性更强。具体来说，切向和径向湿膨胀分别降低了 21.7% 和 11.8%。傅立叶变换红外光谱和 XRD 分析表明，单宁酸的存在催化了半纤维素的降解。此外，水分含量的增加导致 TA 离子化，酸性增强，进一步影响纤维素降解。热重分析表明，TA 通过降低木材成分的初始分解温度和增加木材残重，影响了热处理材料的热稳定性。总之，使用 TA 浸渍和含水率进行预处理可显著提高杉木的尺寸稳定性，并改变其化学成分。这种方法具有相当大的潜力，可在热处理过程中通过低能耗方法提高木材性能，扩大木材的实际应用范围。
{"title":"Effects of tannin acid impregnated pretreatment on dimensional stability and chemical composition of heat-treated Chinese fir","authors":"Yuxin Zhao, Luxi He, Jiayi Kang, Jingjing Gao, Guochen Huo, Kai Xu, Tinghuan Wang, Zhengbin He, Zhenyu Wang, Songlin Yi","doi":"10.1515/hf-2023-0081","DOIUrl":"https://doi.org/10.1515/hf-2023-0081","url":null,"abstract":"Thermal treatment is an effective method for improving the dimensional stability of wood; however, it typically requires high temperatures. To achieve low-temperature heat treatment, this study employed wood samples impregnated with 10 % tannin acid (TA) and examined their changes in dimensional stability and chemical components after heat treatment at various initial moisture content levels. The results revealed that the TA-10 %-HT group exhibited enhanced dimensional stability. Specifically, both the tangential and radial moisture swelling decreased by 21.7 % and 11.8 %, respectively. FTIR and XRD analysis indicated that the presence of tannin acid catalytically facilitated the degradation of hemicellulose. Moreover, an increase in moisture content resulted in the ionization of TA, amplifying acidity and further affecting cellulose degradation. TGA demonstrated that TA impacted the thermal stability of heat-treated materials by lowering the initial decomposition temperature of wood components and increasing the residual weight of wood. Overall, pretreatment with TA impregnation and moisture content significantly improved the dimensional stability of Chinese fir wood and altered its chemical composition. This approach holds considerable potential for enhancing wood properties through a low-energy consumption method during the heat treatment process, expanding the practical application of wood.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139072146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bamboo culm is a natural material characterized by a graded structure of vascular bundles in the radial direction and a regular distribution of bamboo nodes in the axial direction. To investigate the adaptation of bamboo culm structure to its natural environment, the bamboo culm structure was analyzed using a vascular bundle identification model, complemented by mechanical simulations. The results showed a certain pattern in the macroscopic dimensional characteristics of bamboo from the base to the top: the outer diameter decreased linearly; the internode length initially increased before decreasing; the length-to-diameter ratio gradually increased; and the wall-to-cavity ratio initially decreased before increasing. In response to external forces, bamboo exhibited strong stability, which was attributed to the thin and hollow wall as well as parabolic distribution of bamboo nodes. Along the axial direction, vascular bundle numbers linearly decreased, while the ratio of fiber sheath tissue and the distribution frequency of vascular bundles increased from the base to the top. In the radial direction, the length and area of vascular bundles tended to increase before decreasing, while the width tended to increase, leading to a decreasing length-to-width ratio. Overall, the radial variation pattern of vascular bundles showed nonsignificant variations at different heights.
{"title":"Analyzing the structure of bamboo culms using computer vision and mechanical simulation","authors":"Fukuan Dai, Yuxuan Chen, Wenfu Zhang, Tuhua Zhong, Genlin Tian, Hankun Wang","doi":"10.1515/hf-2023-0093","DOIUrl":"https://doi.org/10.1515/hf-2023-0093","url":null,"abstract":"Bamboo culm is a natural material characterized by a graded structure of vascular bundles in the radial direction and a regular distribution of bamboo nodes in the axial direction. To investigate the adaptation of bamboo culm structure to its natural environment, the bamboo culm structure was analyzed using a vascular bundle identification model, complemented by mechanical simulations. The results showed a certain pattern in the macroscopic dimensional characteristics of bamboo from the base to the top: the outer diameter decreased linearly; the internode length initially increased before decreasing; the length-to-diameter ratio gradually increased; and the wall-to-cavity ratio initially decreased before increasing. In response to external forces, bamboo exhibited strong stability, which was attributed to the thin and hollow wall as well as parabolic distribution of bamboo nodes. Along the axial direction, vascular bundle numbers linearly decreased, while the ratio of fiber sheath tissue and the distribution frequency of vascular bundles increased from the base to the top. In the radial direction, the length and area of vascular bundles tended to increase before decreasing, while the width tended to increase, leading to a decreasing length-to-width ratio. Overall, the radial variation pattern of vascular bundles showed nonsignificant variations at different heights.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laise de Jesus dos Santos, Elesandra da Silva Araujo, Mário Sérgio Lorenço, Bianca Bueno Rosário, Sabrina Benmuyal Vieira, Agust Sales, Marco Antonio Siviero, Luiz Eduardo de Lima Melo, Graciene da Silva Mota, Gabriela Aguiar Campolina, Fabio Akira Mori
The bark anatomy was analysed, as was the overall chemical composition (extractives, lignin, suberin, ash and polysaccharides), and a quantitative elemental analysis was performed of the bark and two tannin extracts (extracted with water only and with a mixture of water and Na2SO3). The phenolic composition and antioxidant activity of the bark extracts were quantified. The results indicated that the bark is composed of conductive phloem, nonconductive phloem, rhytidome, crystals and secretory cells. The average chemical composition was 15.9 % extractives, 35.3 % total lignin, 1.9 % suberin, 15.4 % ash and 31.5 % polysaccharides. The condensed tannin yield in the extract obtained with water alone was 5.1 %, and that in the treatment with water and Na2SO3 was 8.1 %. The ethanol-water extract had a high phenolic content (112.6 mg GAE g−1 extract). The bark extract showed strong antioxidant activity, reaching 83.5 % inhibition of DPPH free radicals, which was higher than the value of 75.0 % for the commercial antioxidant BHT at the same concentration. These results demonstrate that Protium tenuifolium is a potential natural Amazonian source of phenolic compounds and antioxidants and can be used for medicinal purposes and the production of various sustainable products, such as cosmetics.
{"title":"Characterization of the bark of Protium tenuifolium Engl. from the Amazonian biome as a source of natural antioxidants","authors":"Laise de Jesus dos Santos, Elesandra da Silva Araujo, Mário Sérgio Lorenço, Bianca Bueno Rosário, Sabrina Benmuyal Vieira, Agust Sales, Marco Antonio Siviero, Luiz Eduardo de Lima Melo, Graciene da Silva Mota, Gabriela Aguiar Campolina, Fabio Akira Mori","doi":"10.1515/hf-2023-0039","DOIUrl":"https://doi.org/10.1515/hf-2023-0039","url":null,"abstract":"The bark anatomy was analysed, as was the overall chemical composition (extractives, lignin, suberin, ash and polysaccharides), and a quantitative elemental analysis was performed of the bark and two tannin extracts (extracted with water only and with a mixture of water and Na<jats:sub>2</jats:sub>SO<jats:sub>3</jats:sub>). The phenolic composition and antioxidant activity of the bark extracts were quantified. The results indicated that the bark is composed of conductive phloem, nonconductive phloem, rhytidome, crystals and secretory cells. The average chemical composition was 15.9 % extractives, 35.3 % total lignin, 1.9 % suberin, 15.4 % ash and 31.5 % polysaccharides. The condensed tannin yield in the extract obtained with water alone was 5.1 %, and that in the treatment with water and Na<jats:sub>2</jats:sub>SO<jats:sub>3</jats:sub> was 8.1 %. The ethanol-water extract had a high phenolic content (112.6 mg GAE g<jats:sup>−1</jats:sup> extract). The bark extract showed strong antioxidant activity, reaching 83.5 % inhibition of DPPH free radicals, which was higher than the value of 75.0 % for the commercial antioxidant BHT at the same concentration. These results demonstrate that <jats:italic>Protium tenuifolium</jats:italic> is a potential natural Amazonian source of phenolic compounds and antioxidants and can be used for medicinal purposes and the production of various sustainable products, such as cosmetics.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139051083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jaco-Pierre van der Merwe, Martin Bacher, Sechaba Madiope, Thandekile Ncongwane, Robert Ngomane, Olwethu Spogter, Hilton Kuisis, Jaco Potgieter, Oscar Tait, Charlie Clarke, Julie Cool, Stavros Avramidis, Simon Ellis, Shawn D. Mansfield
South Africa is a water scarce country with minimal natural forests. Plantation forest species such as the Mexican tropical hard pine, Pinus patula Schiede & Deppe ex Schltdl. & Cham., was introduced into the country to satisfy local fibre demand. Today, the majority of pine plantations in South Africa are found in the Mpumalanga province. The province has diverse growing conditions in relation to climate and soil properties. Sample plots were established in even-aged P. patula plantations and stratified according to soil parent material and altitude. Growing conditions of each sample plot were characterised according to climate and soil properties. A total of 540 sample trees were measured for height, diameter, density, and latewood content. The sample trees were harvested to produce 2690 logs. The logs were milled, and the resultant lumber was graded according to density, dynamic modulus of elasticity, and modulus of rupture. Annual maximum temperature had the most significant impact on tree growth, while rainfall correlated with wood density and latewood content of standing trees. However, annual maximum temperature and tree height had a negative relationship with the recovered lumber properties and dimensional stability. Spring rainfall appeared to be the most important factor influencing lumber twist and this was possibly due to the associated larger juvenile core present in the trees.
南非是一个缺水国家，天然森林极少。为了满足当地的纤维需求，该国引进了墨西哥热带硬松（Pinus patula Schiede & Deppe ex Schltdl.如今，南非大部分的松树种植园都位于姆普马兰加省。该省的气候和土壤条件各不相同。我们在树龄均匀的 P. patula 人工林中建立了样地，并根据土壤母质和海拔高度进行了分层。根据气候和土壤特性对每个样地的生长条件进行了描述。共测量了 540 棵样树的高度、直径、密度和晚材含量。样本树被采伐后产生了 2690 根原木。原木经过碾磨后，根据密度、动态弹性模量和断裂模数对木材进行分级。年最高气温对树木生长的影响最大，而降雨量则与立木的木材密度和晚材含量相关。然而，年最高气温和树高与木材的恢复特性和尺寸稳定性呈负相关。春季降雨似乎是影响木材捻度的最重要因素，这可能是由于树木中存在较大的幼核。
{"title":"The impact of site on tree form, wood properties, and lumber quality of plantation-grown Pinus patula","authors":"Jaco-Pierre van der Merwe, Martin Bacher, Sechaba Madiope, Thandekile Ncongwane, Robert Ngomane, Olwethu Spogter, Hilton Kuisis, Jaco Potgieter, Oscar Tait, Charlie Clarke, Julie Cool, Stavros Avramidis, Simon Ellis, Shawn D. Mansfield","doi":"10.1515/hf-2023-0075","DOIUrl":"https://doi.org/10.1515/hf-2023-0075","url":null,"abstract":"South Africa is a water scarce country with minimal natural forests. Plantation forest species such as the Mexican tropical hard pine, <jats:italic>Pinus patula</jats:italic> Schiede & Deppe <jats:italic>ex</jats:italic> Schltdl. & Cham.<jats:italic>,</jats:italic> was introduced into the country to satisfy local fibre demand. Today, the majority of pine plantations in South Africa are found in the Mpumalanga province. The province has diverse growing conditions in relation to climate and soil properties. Sample plots were established in even-aged <jats:italic>P. patula</jats:italic> plantations and stratified according to soil parent material and altitude. Growing conditions of each sample plot were characterised according to climate and soil properties. A total of 540 sample trees were measured for height, diameter, density, and latewood content. The sample trees were harvested to produce 2690 logs. The logs were milled, and the resultant lumber was graded according to density, dynamic modulus of elasticity, and modulus of rupture. Annual maximum temperature had the most significant impact on tree growth, while rainfall correlated with wood density and latewood content of standing trees. However, annual maximum temperature and tree height had a negative relationship with the recovered lumber properties and dimensional stability. Spring rainfall appeared to be the most important factor influencing lumber twist and this was possibly due to the associated larger juvenile core present in the trees.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research focuses on increasing wood resistance against UV degradation using trimethoxyphenylsilane as modifying agent and supercritical CO2 as a green solvent and reaction medium. Trimethoxyphenylsilane was successfully grafted on European spruce (Picea abies, H. Karst) and was characterized by SEM-EDX and UV–vis reflectance. SEM-EDX showed the presence of silicium inside the wood cell wall. Increased wood moisture content showed positive effect on weight gain of trimethoxyphenylsilane after treatment. UV resistance of treated wood was evaluated by following the color change during artificial weathering. Modified samples showed improved weathering resistance compared to unmodified wood with a ΔE value around 5 after 260 h. Processing and modifying wood using supercritical CO2 is a promising route to increase wood performances and increase its use as a building material.
以三甲氧基苯基硅烷为改性剂，超临界CO2为绿色溶剂和反应介质，研究提高木材抗紫外线降解能力的方法。将三甲氧基苯基硅烷成功地接枝在欧洲云杉(Picea abies, H. Karst)上，并用SEM-EDX和紫外-可见反射率对其进行了表征。SEM-EDX显示木材细胞壁内有硅的存在。处理后木材含水率的增加对三甲氧基苯基硅烷增重有积极影响。通过观察人工风化过程中木材的颜色变化来评价木材的抗紫外线性能。与未改性木材相比，改性样品在260 h后的耐候性得到了改善，其ΔE值约为5。使用超临界二氧化碳对木材进行加工和改性是提高木材性能和增加其作为建筑材料用途的有希望的途径。
{"title":"Wood modification with trimethoxyphenylsilane via supercritical carbon dioxide for enhanced weathering resistance","authors":"Juliette Triquet, Olivier Renard, Pierre Piluso","doi":"10.1515/hf-2023-0089","DOIUrl":"https://doi.org/10.1515/hf-2023-0089","url":null,"abstract":"This research focuses on increasing wood resistance against UV degradation using trimethoxyphenylsilane as modifying agent and supercritical CO<jats:sub>2</jats:sub> as a green solvent and reaction medium. Trimethoxyphenylsilane was successfully grafted on European spruce (<jats:italic>Picea abies</jats:italic>, H. Karst) and was characterized by SEM-EDX and UV–vis reflectance. SEM-EDX showed the presence of silicium inside the wood cell wall. Increased wood moisture content showed positive effect on weight gain of trimethoxyphenylsilane after treatment. UV resistance of treated wood was evaluated by following the color change during artificial weathering. Modified samples showed improved weathering resistance compared to unmodified wood with a Δ<jats:italic>E</jats:italic> value around 5 after 260 h. Processing and modifying wood using supercritical CO<jats:sub>2</jats:sub> is a promising route to increase wood performances and increase its use as a building material.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138630022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To develop an eco-friendly artificial turf filling for replacing rubber elastomer particles, seven kinds of natural materials (cork, soft oak, champagne bark, oak bark, pine bark, willow bark, and vermiculite) were selected and processed into particles with a dimension of 1–2 mm. The water absorption performance, mold resistance, resilience, compression characteristics, and the repose angle were tested, and the surface microscopic morphology of granular materials was observed. The experimental results showed that the champagne bark had the largest plastic deformation range under pressure load, which was 0.21–7.82 KN. And the champagne bark particles had the best resilience, which was respectively 8.9 % and 7.1 % before and after compression, and its angle of repose was 36.8°, which was 9 % higher than that of the thermoplastic elastomer (TPE) particle. Additionally, champagne bark had better mold resistance compared with the other six natural materials, and its mold only occurred in the mold inoculation center. In conclusion, champagne bark could be considered as an artificial turf filling granule to replace TPE rubber.
{"title":"The feasibility and properties of wood used as filler in artificial turf to reduce environment pollution","authors":"Luyang Wang, Ke Shi, Chunxia He","doi":"10.1515/hf-2023-0047","DOIUrl":"https://doi.org/10.1515/hf-2023-0047","url":null,"abstract":"To develop an eco-friendly artificial turf filling for replacing rubber elastomer particles, seven kinds of natural materials (cork, soft oak, champagne bark, oak bark, pine bark, willow bark, and vermiculite) were selected and processed into particles with a dimension of 1–2 mm. The water absorption performance, mold resistance, resilience, compression characteristics, and the repose angle were tested, and the surface microscopic morphology of granular materials was observed. The experimental results showed that the champagne bark had the largest plastic deformation range under pressure load, which was 0.21–7.82 KN. And the champagne bark particles had the best resilience, which was respectively 8.9 % and 7.1 % before and after compression, and its angle of repose was 36.8°, which was 9 % higher than that of the thermoplastic elastomer (TPE) particle. Additionally, champagne bark had better mold resistance compared with the other six natural materials, and its mold only occurred in the mold inoculation center. In conclusion, champagne bark could be considered as an artificial turf filling granule to replace TPE rubber.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138530994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md. Tipu Sultan, Daniela Altgen, Muhammad Awais, Lauri Rautkari, Michael Altgen
The dimensional stabilisation of wood using thermosetting resins relies on the resin uptake into the cell walls. This study tested if a conditioning step after the impregnation and before the final heat-curing enhances the cell wall uptake to improve dimensional stabilisation without increasing the chemical consumption. Small blocks of Scots pine sapwood were vacuum-impregnated with an aqueous melamine formaldehyde solution and conditioned at 33, 70, or 95 % RH for up to 1 week before drying and curing the blocks at 103 °C. However, the conditioning step decreased the cell wall bulking and the moisture exclusion effect compared to the immediate heat curing of the impregnated samples. Analyses of the resin-treated samples by scanning electron microscopy, IR spectroscopy and confocal Raman microspectroscopy provided evidence of wood hydrolysis and polycondensation of the resin within the cell lumen during the conditioning step. Hydrolysis and removal of wood constituents may have counterbalanced the cell wall bulking of the resin. Polycondensation of the resin in the lumen increased its molecule size, which could have hindered the cell wall diffusion of the resin.
{"title":"Impact of a conditioning step during the treatment of wood with melamine-formaldehyde resin on dimensional stabilisation","authors":"Md. Tipu Sultan, Daniela Altgen, Muhammad Awais, Lauri Rautkari, Michael Altgen","doi":"10.1515/hf-2023-0084","DOIUrl":"https://doi.org/10.1515/hf-2023-0084","url":null,"abstract":"The dimensional stabilisation of wood using thermosetting resins relies on the resin uptake into the cell walls. This study tested if a conditioning step after the impregnation and before the final heat-curing enhances the cell wall uptake to improve dimensional stabilisation without increasing the chemical consumption. Small blocks of Scots pine sapwood were vacuum-impregnated with an aqueous melamine formaldehyde solution and conditioned at 33, 70, or 95 % RH for up to 1 week before drying and curing the blocks at 103 °C. However, the conditioning step decreased the cell wall bulking and the moisture exclusion effect compared to the immediate heat curing of the impregnated samples. Analyses of the resin-treated samples by scanning electron microscopy, IR spectroscopy and confocal Raman microspectroscopy provided evidence of wood hydrolysis and polycondensation of the resin within the cell lumen during the conditioning step. Hydrolysis and removal of wood constituents may have counterbalanced the cell wall bulking of the resin. Polycondensation of the resin in the lumen increased its molecule size, which could have hindered the cell wall diffusion of the resin.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138530952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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