Holzforschung最新文献_第3页

Dynamic diffusion in softwood and hardwood cell walls using fluorescence recovery after photobleaching 利用光漂白后的荧光恢复技术研究软木和硬木细胞壁的动态扩散情况

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-04-21 DOI: 10.1515/hf-2024-0007

Lloyd Donaldson, Hamish Pearson

{"title":"Dynamic diffusion in softwood and hardwood cell walls using fluorescence recovery after photobleaching","authors":"Lloyd Donaldson, Hamish Pearson","doi":"10.1515/hf-2024-0007","DOIUrl":"https://doi.org/10.1515/hf-2024-0007","url":null,"abstract":"The porosity of cell walls, as indicated by diffusion of rhodamine B dye, in the wood of Douglas fir, radiata pine, New Zealand red beech and Shining gum was compared under dynamic conditions using fluorescence recovery after photobleaching. The comparative diffusion rate was estimated using the half-life of fluorescence recovery under water-saturated conditions performed on transverse sections. All four wood species showed similar diffusion behaviour in tracheid or fibre cell walls with slower diffusion in the middle lamella layer compared to the secondary cell wall. Within the S2 layer of the secondary wall two regions were observed, an outer region with a slow diffusion rate and an inner region with a higher diffusion rate. Vessel cell walls showed slightly slower diffusion rates. Diffusion of rhodamine B dye appears to occur primarily along the fibre axis and is probably somewhat different to water in its behaviour. This suggests that pores are aligned with cellulose microfibrils. The dye diffusion rate was estimated to be in the range of 50–100 nm2 s−1. This has implications for understanding wood drying behaviour and chemical modification of wood by infiltration with small molecules as well as water storage in living trees.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"100 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140630180","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}

引用次数: 0

Impact of surface delignification on fire retardancy of wood treated with polyelectrolyte complexes 表面脱木素对用聚电解质复合物处理的木材阻燃性的影响

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-27 DOI: 10.1515/hf-2023-0059

Marie Soula, Fabienne Samyn, Sophie Duquesne, Véronic Landry

{"title":"Impact of surface delignification on fire retardancy of wood treated with polyelectrolyte complexes","authors":"Marie Soula, Fabienne Samyn, Sophie Duquesne, Véronic Landry","doi":"10.1515/hf-2023-0059","DOIUrl":"https://doi.org/10.1515/hf-2023-0059","url":null,"abstract":"Wood is a natural composite widely employed as a residential building interior finishing. Although wood is readily available and offers benefits to the occupants, such as enhanced well-being, it is rarely employed in commercial construction due, amongst others, to the potential hazard of fire propagation. The application of flame retardant (FR) treatments leads to a reduction of wood flammability and supports wood as interior finishing. Polyelectrolyte complexes (PECs) deposition is an innovative surface treatment that has already proven its efficiency for fabrics. For wood, recent studies have highlighted that the weight gain impacted the fire-retardancy, and a minimum of 2 wt.-% was set to obtain fire protection. This study explored the potential of surface delignification to activate the wood surface and facilitate the PEC impregnation. Yellow birch (Betula alleghaniensis, Britt.) was surface delignified (0.3 mm) using sodium chlorite. The treatment impact on wood was evaluated by spectroscopy analysis (FTIR, Raman), and the increase in wood wettability was demonstrated (contact angle decreases from 50° to 35° after the surface delignification). Then, PECs consisting of polyethyleneimine and sodium phytate were surface impregnated in wood and delignified wood. The flame retardancy was evaluated using a cone calorimeter. Despite the increase in weight gain (1.5 wt.-% ± 0.3 wt.-% to 4.3 wt.-% ± 2.5 wt.-%), fire performance was not improved. This study demonstrates that lignin strongly affects char formation, even in the presence of PECs.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"30 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315856","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}

引用次数: 0

A study of dimensional effects on the stress characteristics of Yunnan pine shafts considering seismic strain rates 考虑地震应变率的云南松竖井应力特性的尺寸效应研究

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-25 DOI: 10.1515/hf-2023-0098

Jianhui Liu, Guolin Xu, Yashuang Bai, Yujie Lin, Wenqing Geng

{"title":"A study of dimensional effects on the stress characteristics of Yunnan pine shafts considering seismic strain rates","authors":"Jianhui Liu, Guolin Xu, Yashuang Bai, Yujie Lin, Wenqing Geng","doi":"10.1515/hf-2023-0098","DOIUrl":"https://doi.org/10.1515/hf-2023-0098","url":null,"abstract":"The mechanical properties of wood are affected by member size and loading rate. Axial compression tests with different seismic strain rates and sizes of specimens were carried out to investigate the static and dynamic dimensional effects of Yunnan pine timber. And obtained load-displacement curves, compressive strength, modulus of elasticity, peak strain and Poisson’s ratio. Weibull’s weakest chain theory, Bazant’s law of dimensional effects and Carpinteri’s law of multiple fractal dimensional effects were used to analyze the dimensional effects on the compressive strength of wood, and to establish a wood strength model that takes strain rate effects and dimensional effects into account. The results showed that the compressive strength, elastic modulus, and Poisson’s ratio of Yunnan pine wood exhibit both size and strain rate effects. Under the coupling effect of strain rate effect and size effect, the size effect of Yunnan pine wood strength decreases with increasing strain rate, while the strain rate effect increases with increasing size. A size effect model for compressive strength of wood considering strain rate effect based on three theories and experimental data can well describe the dynamic size effect of Yunnan pine wood strength.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"13 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140303331","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}

引用次数: 0

Poplar wood treated with nano-silver–copper particles: fungal degradation and leaching analysis 用纳米银铜颗粒处理的杨木：真菌降解和沥滤分析

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-25 DOI: 10.1515/hf-2023-0128

Xiwei Wang, Tengfei Yi, Hongxue Luo, Yanran Qi, Fengbiao Yao, Yiliang Liu, Yongfeng Li

{"title":"Poplar wood treated with nano-silver–copper particles: fungal degradation and leaching analysis","authors":"Xiwei Wang, Tengfei Yi, Hongxue Luo, Yanran Qi, Fengbiao Yao, Yiliang Liu, Yongfeng Li","doi":"10.1515/hf-2023-0128","DOIUrl":"https://doi.org/10.1515/hf-2023-0128","url":null,"abstract":"This study investigated the inhibition effect of nanoscale silver–copper particle (20 nm) against Coriolus versicolor and Gloeophyllum trabeum. Poplar wood samples (Populus L.) were vacuum-impregnated using aqueous nano-AgCu solutions at concentrations of 0.01 %, 0.02 %, 0.03 %, 0.05 %, 0.075 %, and 0.1 %. Alkaline copper quaternary (ACQ, 0.1 %), boric acid (0.2 %) and untreated control group (CK) were employed for comparisons. Decay resistance and leachability were studied. The anti-fungi effects were compared between nano-AgCu, nano-Ag, Ag+ (silver nitrate), Cu2+ (copper nitrate), and a composite of Ag+–Cu2+. Nano-AgCu particle exhibited effective resistance to fungi after 12 weeks of exposure. The threshold retention of the nano-AgCu against C. versicolor and G. trabeum on poplar wood was 0.19 kg m−3 and 0.62 kg m−3, respectively. The silver–copper nanoparticles demonstrated excellent leach resistance, and the inhibition effect was retained after leaching. The nano-AgCu particle provided better antifungal effects than single ions or metal nanoparticles. This study illustrates the potential of using nano-AgCu particle as an efficient wood preservative compared to commercial water-soluble preservatives.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"30 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140301534","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}

引用次数: 0

Photodegradation stability of huminated European pine (Pinus sylvestris L.) microveneers 腐殖化欧洲松树（Pinus sylvestris L.）微文素的光降解稳定性

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-19 DOI: 10.1515/hf-2024-0006

Amir Ghavidel, Reza Hosseinpourpia

{"title":"Photodegradation stability of huminated European pine (Pinus sylvestris L.) microveneers","authors":"Amir Ghavidel, Reza Hosseinpourpia","doi":"10.1515/hf-2024-0006","DOIUrl":"https://doi.org/10.1515/hf-2024-0006","url":null,"abstract":"Humins are heterogeneous and polydisperse furanic macromolecules derived from sugar biorefinery. Improving wood properties by humination has become of interest recently. This study examined the photodegradation stability of European pine sapwood microveneers modified with humins at different concentrations of citric acid (CA) and succinic acid (SA) as reaction catalysts, e.g., 1.5 %, 3 %, and 4.5 % wt.%. The photostability of huminated wood was assessed after 48 h, 96 h, and 144 h of exposure to the accelerated weathering test by means of mass loss and finite-span tensile strength. The results were compared with unmodified and also unweathered samples. The FT-IR spectroscopy showed apparent changes in the chemical structure of wood by humination modifications. The weight percentage gains of the samples increased with increasing the concentration of the catalyst. While no differences were observed between the samples after two weeks of the water leaching. The strength losses of weathered microveneers were, however, mostly reduced by humin-based formulas containing catalysts, where the microveneers modified with 1.5 % and 3 % CA showed respectively 32 % and 41 % lower strength loss values than the unmodified samples after 144 h of weathering. Overall, the results showed a high potential for humins to protect wood against photodegradation.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"36 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140171060","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}

引用次数: 0

Douglas fir bark: composition, extracts utilization and enzymatic treatment for enrichment of bioactive constituents 花旗松树皮：成分、提取物利用和酶处理以丰富生物活性成分

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-11 DOI: 10.1515/hf-2023-0130

Lukas Sommerauer, Matthew Konkler, Gerald Presley, Thomas Schnabel, Alexander Petutschnigg, Barbara Hinterstoisser

{"title":"Douglas fir bark: composition, extracts utilization and enzymatic treatment for enrichment of bioactive constituents","authors":"Lukas Sommerauer, Matthew Konkler, Gerald Presley, Thomas Schnabel, Alexander Petutschnigg, Barbara Hinterstoisser","doi":"10.1515/hf-2023-0130","DOIUrl":"https://doi.org/10.1515/hf-2023-0130","url":null,"abstract":"Bark residues from Douglas fir are an abundant resource that is currently used primarily in low-value energy recovery or is landfilled. Bark extractives are rich in diverse compounds like terpenes, fatty acids, phenols, and sugars with potential uses in a variety of high value applications. The study explores the potential of enzymatic hydrolysis to improve phenolic compounds from Douglas fir bark. It also assesses differences in chemical composition among rhytidome, phloem, and comingled bark fractions from an industrial waste pile. Phloem fractions exhibit higher yields of extractives, rhytidome fractions have elevated lignin levels, while the comingled fraction lies between the two except in ash content which was higher than in the separated fractions. Fungal decay tests with Gloeophyllum trabeum and Coniophora puteana on extract treated wood suggest potential for growth inhibition in extracts, about 58–31 % and 30–7% mass loss (in average) respectively, but due to high mass loss at low concentrations an enzymatic modification approach seems crucial for enhanced inhibition. Growth responses in whole-cell fermentation approach display variability depending on the participating microorganisms. Enzymatic hydrolysis with beta-glucosidase improved the antioxidant properties of bark extracts and holds promise for altering the chemical composition and enhancing bioactivity.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"17 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140108179","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}

引用次数: 0

Synthesis of hydrophobic biopolyesters from depolymerized Pinus radiata bark suberin 从解聚的欧洲赤松树皮单宁中合成疏水性生物聚酯

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-11 DOI: 10.1515/hf-2023-0104

Helena C. Quilter, Regis Risani, Suzanne Gallagher, Michael Robertson, Armin Thumm, Hayden P. Thomas, Robert Abbel

{"title":"Synthesis of hydrophobic biopolyesters from depolymerized Pinus radiata bark suberin","authors":"Helena C. Quilter, Regis Risani, Suzanne Gallagher, Michael Robertson, Armin Thumm, Hayden P. Thomas, Robert Abbel","doi":"10.1515/hf-2023-0104","DOIUrl":"https://doi.org/10.1515/hf-2023-0104","url":null,"abstract":"The bark of Pinus radiata offers an underutilized source of high-value renewable chemicals such as extractable polyphenols and lipophilic compounds (waxes and suberin). Here, the depolymerization and extraction of suberin from P. radiata bark and its repolymerization to form novel polyesters are reported. Three different strategies were evaluated for repolymerization of the suberin monomers, with starting materials and products characterized using chemical and thermal analysis techniques. The inclusion of comonomer (1,12-dodecanediol) to provide stoichiometric balance improved the conversion, product yield, solubility and increased molecular weight. Enzymatic polymerization conditions gave the highest yield, while the highest molecular weight was achieved using titanium butoxide, demonstrating that polymerization conditions could be varied to target desired product properties. Products were hydrophobic, as shown by contact angles, ϴ ≥ 90° after 30 s. This work highlights opportunities for utilizing suberin to add value to a P. radiata bark biorefinery concept. Potential future applications include its use as a starting material for novel bio-based polymers that can serve as water-repellent surfaces and coatings, replacing established products derived from fossil resources.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"37 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140105268","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}

引用次数: 0

Resistance against fungal decay of Scots pine sapwood modified with phenol-formaldehyde resins with substitution of phenol by lignin pyrolysis products 用木质素热解产物替代苯酚的苯酚-甲醛树脂改性的苏格兰松树边材的抗真菌腐烂能力

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-07 DOI: 10.1515/hf-2023-0119

Johannes Karthäuser, Andreas Treu, Erik Larnøy, Holger Militz, Gry Alfredsen

{"title":"Resistance against fungal decay of Scots pine sapwood modified with phenol-formaldehyde resins with substitution of phenol by lignin pyrolysis products","authors":"Johannes Karthäuser, Andreas Treu, Erik Larnøy, Holger Militz, Gry Alfredsen","doi":"10.1515/hf-2023-0119","DOIUrl":"https://doi.org/10.1515/hf-2023-0119","url":null,"abstract":"Phenol-formaldehyde (PF) resins can be impregnated and cured in situ to improve the woods dimensional stability and decay resistance. In search of renewable alternatives, the substitution of phenol by lignin cleavage products (LCP) has been discussed. However, the different chemical nature may affect the performance of the resin against fungal decay, formaldehyde emission, and equilibrium moisture content. In this study, 30 % (w/w) of the phenol in PF resins were substituted by LCP obtained from microwave-assisted pyrolysis. Scots pine sapwood was modified with the resin. The decay resistance against Rhodonia placenta, Gloeophyllum trabeum, and Trametes versicolor was determined. Additionally, effects of specimen organisation within the Petri dish, different substrates, length of leaching, and type of inoculum were studied. Further, the materials water vapor sorption properties and formaldehyde emission were determined. All modifications effectively reduced fungal decay. With 10 % weight percent gain (WPG), initial decay was detected, while 20 % WPG and 30 % WPG provided efficient protection. The substitution of phenol increases the formaldehyde emission. While further reduction in formaldehyde in the resin admixture or formaldehyde scavengers may be required, the method described herein can be used to partly replace fossil-based phenol, while maintaining good fungal resistance.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"37 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074415","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}

引用次数: 0

Shrinkage of poplar and radiata pine wood after treatment with sodium silicate and sodium hydroxide 杨木和辐射松经硅酸钠和氢氧化钠处理后的收缩率

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-06 DOI: 10.1515/hf-2023-0097

Thi Tham Nguyen, Cong Chi Tran, Thi Vinh Khanh Nguyen, Trong Kien Nguyen, Zefang Xiao, Yanjun Xie

{"title":"Shrinkage of poplar and radiata pine wood after treatment with sodium silicate and sodium hydroxide","authors":"Thi Tham Nguyen, Cong Chi Tran, Thi Vinh Khanh Nguyen, Trong Kien Nguyen, Zefang Xiao, Yanjun Xie","doi":"10.1515/hf-2023-0097","DOIUrl":"https://doi.org/10.1515/hf-2023-0097","url":null,"abstract":"Chemical modification is an efficient strategy for improving wood quality; however, for some fast-grown wood species unwanted shrinkage occur upon treatment with alkaline solution. This study was devised to reveal the shrinkage behavior of poplar and radiata pine woods treated with 5, 10, 15 and 20 % alkaline sodium silicate (SS) solutions. Wood treated with sodium hydroxide (SH) solution adjusting to the same pH as the specific SS solution was used as a reference sample. The weight loss, chemical components analysis, and confocal microscopy revealed that treatments with SS caused considerable reductions in hemicellulose and acid-insoluble lignin (AIL) of poplar wood up to 51 % and 21 %, respectively. In contrast, such reductions of the SS-treated radiata pine wood were only 13 % and 2 %, respectively. Consequently, shrinkage of poplar wood in the tangential- and radial-directions reached up to 22 % and 11 % respectively. However, such shrinkage for radiata pine was less than 2 % in either direction. The crystallinity index of poplar and radiata pine woods after treatment increased up to 35.3 % and 4.8 %, respectively, attributable to removal of the amorphous fraction. The scanning electron microscopy displayed that treatments had minor effect on the cell structure of radiata pine, but brought about significant collapse of poplar cells. The above results show that radiata pine is more chemically stable to alkaline treatment than poplar.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"27 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140057691","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}

引用次数: 0

The glass transition temperature of isolated native, residual, and technical lignin 分离的原生木质素、残留木质素和工业木质素的玻璃化转变温度

IF 2.4 3区农林科学

Holzforschung Pub Date : 2024-03-04 DOI: 10.1515/hf-2023-0111

Åke Henrik-Klemens, Fabio Caputo, Roujin Ghaffari, Gunnar Westman, Ulrica Edlund, Lisbeth Olsson, Anette Larsson

{"title":"The glass transition temperature of isolated native, residual, and technical lignin","authors":"Åke Henrik-Klemens, Fabio Caputo, Roujin Ghaffari, Gunnar Westman, Ulrica Edlund, Lisbeth Olsson, Anette Larsson","doi":"10.1515/hf-2023-0111","DOIUrl":"https://doi.org/10.1515/hf-2023-0111","url":null,"abstract":"The glass transition temperatures (T g) of native, residual, and technical lignins are important to lignocellulose pulping, pulp processing and side stream utilization; however, how the structural changes from native to residual and technical lignin influences T g has proven difficult to elucidate. Since the T g of macromolecules is greatly influenced by the molecular weight, low-molecular-weight fractions, such as milled wood lignin (MWL), are poor representatives of lignin in the cell wall. To circumvent this problem, lignins of both high yield and purity were isolated from Norway spruce and softwood kraft pulp using the enzymatic mild acidolysis lignin (EMAL) protocol. Technical softwood kraft lignin was also fractionated into groups of different molecular weights, to acquire lignin that spanned over a wide molecular-weight range. A powder sample holder for dynamic mechanical analysis (DMA), was used to determine the T g of lignins, for which calorimetric methods were not sensitive enough. The T gs of EMAL were found to be closer to their in situ counterparts than MWL.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"11 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140034304","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}

引用次数: 0