Analysis on SNPs linked with wood properties of <I>Populus nigra</I>L. gene resources

Swelling and water resistance of black poplar wood (Populus nigra L.) modified by polymerisation in lumen with styrene. Polymerisation in lumen of black poplar (Populus nigra L.) was performed to improve wood properties related to interaction with water. Wood samples were modified with styrene or a mixture of styrene and maleic anhydride, using benzoyl peroxide as initiator. Polymerisation was conducted in closed vessels at a temperature up to 120 °C. Volume swelling and water absorbability of modified wood samples were measured. A significant decrease in the rate of water absorption was found, especially at the initial stage of soaking, resulting in 50 % decrease in volume swelling and 85 % decrease in water absorption.

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Chemical composition as factor affecting the mechanical properties of thermally modified black poplar (Populus nigra L.)

BioResources ◽

10.15376/biores.15.2.3915-3929 ◽

2020 ◽

Vol 15 (2) ◽

pp. 3915-3929

Author(s):

Paweł Kozakiewicz ◽

Michał Drożdżek ◽

Agnieszka Laskowska ◽

Marek Grześkiewicz ◽

Olga Bytner ◽

...

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Thermal Processing ◽

Wood Properties ◽

Populus Nigra ◽

Modulus Of Rupture ◽

Wood Moisture ◽

Black Poplar ◽

Thermally Modified Wood ◽

Modified Wood

Black poplar (Populus nigra L.) was thermally modified in superheated steam at 160 °C, 190 °C, and 220 °C for 2 h. The research identified correlations between the chemical composition and selected mechanical properties of thermally modified wood. The higher treatment temperatures significantly lowered the modulus of rupture (MOR) and the Brinell hardness (BH). These correlations were particularly apparent at higher temperatures (190 °C and 220 °C) when thermally modified wood experienced stronger hemicelluloses degradation, which was indicated by an increase in the content of non-structural substances. The wood properties including compressive strength parallel to the grain (CS), modulus of elasticity during bending (MOE), and compressing (MCS) were affected less by the chemical changes caused by the thermal processing of wood. Moreover, the level of wood moisture content also affected these changes.

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FEEDBACK OF WATER STRESS ON WOOD PROPERTIES OF TREES: EXPERIMENTS WITH MISTLETOES ON RHODODENDRON ARBOREUM SM.

Ecoprint An International Journal of Ecology ◽

10.3126/eco.v11i1.140 ◽

1970 ◽

Vol 11 (1) ◽

Author(s):

Mohan P. Devkota ◽

Gerhard Glatzel

Keyword(s):

Water Stress ◽

Wood Anatomy ◽

Wood Properties ◽

Vessel Diameter ◽

Conservation Area ◽

Rhododendron Arboreum ◽

Central Nepal ◽

Inhibition Of Growth ◽

Infected Area ◽

Anatomical Parameters

Effects of infection by the mistletoe Scurrula elata (Edgew.) Danser, on wood properties of its common host Rhododendron arboreum Sm., were studied in the Annapurna Conservation Area of Central Nepal Himalaya. Heavy infection by mistletoes invariably causes decline of the host. Infested branches show inhibition of growth, defoliation and eventual death of branch parts distal to the site of infection. Anatomical properties of wood were compared in samples of branches proximal to the infection and in uninfected branches. The hypothesis that infection induces changes in basic wood anatomy could not be proven. Vessel density, vessel area, percentage lumen area and mean vessel diameter of the wood of infested and uninfected branches did not show any significant differences. The studied anatomical parameters were not correlated to the diameter of the host branch. These results show that infection by S. elata did not cause any changes in basic wood anatomy of its host R. arboreum. It appears that the studied anatomical parameters of Rhododendron wood are fairly stable and are not changed by stress due to infection by mistletoes. The damage to the host distal to the infected area most likely results from an insufficiency of total conductive area to supply both mistletoe and host. Unfortunately we could not determine annual conductive area increment, because R arboreum does not develop usable annual tree rings in the climate of the study area. Key words: Himalayas, mistletoe. Rhododendron arboreum, Scurrula elata, water stress, wood anatomy. Ecoprint Vol.11(1) 2004.

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Effect of Furfurylation on Hierarchical Porous Structure of Poplar Wood

Polymers ◽

10.3390/polym13010032 ◽

2020 ◽

Vol 13 (1) ◽

pp. 32

Author(s):

Xiaoshuang Shen ◽

Pan Jiang ◽

Dengkang Guo ◽

Gaiyun Li ◽

Fuxiang Chu ◽

...

Keyword(s):

Porous Structure ◽

Value Added ◽

Untreated Wood ◽

Weight Percent Gain ◽

Wood Properties ◽

Weight Percent ◽

Acoustic Properties ◽

Hierarchical Porous Structure ◽

Wood Processing ◽

Hierarchical Porous

Some wood properties (such as permeability and acoustic properties) are closely related to its hierarchical porous structure, which is responsible for its potential applications. In this study, the effect of wood impregnation with furfuryl alcohol on its hierarchical porous structure was investigated by microscopy, mercury intrusion porosimetry and nuclear magnetic resonance cryoporometry. Results indicated decreasing lumina diameters and increasing cell wall thickness of various cells after modification. These alterations became serious with enhancing weight percent gain (WPG). Some perforations and pits were also occluded. Compared with those of untreated wood, the porosity and pore volume of two furfurylated woods decreased at most of the pore diameters, which became more remarkable with raising WPG. The majority of pore sizes (diameters of 1000~100,000 nm and 10~80 nm) of macrospores and micro-mesopores of two furfurylated woods were the same as those of untreated wood. This work could offer thorough knowledge of the hierarchical porous structure of impregnatedly modified wood and pore-related properties, thereby providing guidance for subsequent wood processing and value-added applications.

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Hybrid Approach for Wood Modification: Characterization and Evaluation of Weathering Resistance of Coatings on Acetylated Wood

Coatings ◽

10.3390/coatings11060658 ◽

2021 ◽

Vol 11 (6) ◽

pp. 658

Author(s):

Anna Sandak ◽

Edit Földvári-Nagy ◽

Faksawat Poohphajai ◽

Rene Herrera Diaz ◽

Oihana Gordobil ◽

...

Keyword(s):

Service Life ◽

Hybrid Approach ◽

Wood Properties ◽

Wood Products ◽

Superior Performance ◽

Surface Erosion ◽

Coating Film ◽

Chemical Treatments ◽

Cellular Wall ◽

Bulk Substrate

Wood, as a biological material, is sensitive to environmental conditions and microorganisms; therefore, wood products require protective measures to extend their service life in outdoor applications. Several modification processes are available for the improvement of wood properties, including commercially available solutions. Among the chemical treatments, acetylation by acetic anhydride is one of the most effective methods to induce chemical changes in the constitutive polymers at the cellular wall level. Acetylation reduces wood shrinkage-swelling, increases its durability against biotic agents, improves UV resistance and reduces surface erosion. However, even if the expected service life for external cladding of acetylated wood is estimated to be 60 years, the aesthetics change rapidly during the first years of exposure. Hybrid, or fusion, modification includes processes where the positive effect of a single treatment can be multiplied by merging with additional follow-up modifications. This report presents results of the performance tests of wood samples that, besides the modification by means of acetylation, were additionally protected with seven commercially available coatings. Natural weathering was conducted in Northern Italy for 15 months. Samples were characterized with numerous instruments by measuring samples collected from the stand every three months. Superior performance was observed on samples that merged both treatments. It is due to the combined effect of the wood acetylation and surface coating. Limited shrinkage/swelling of the bulk substrate due to chemical treatment substantially reduced stresses of the coating film. Hybrid process, compared to sole acetylation of wood, assured superior visual performance of the wood surface by preserving its original appearance.

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Selection of Eucalyptus camaldulensis Families for Sustainable Pulpwood Production by Means of Anatomical Characteristics

Forests ◽

10.3390/f12010031 ◽

2020 ◽

Vol 12 (1) ◽

pp. 31

Author(s):

Ikumi Nezu ◽

Futoshi Ishiguri ◽

Haruna Aiso ◽

Sapit Diloksumpun ◽

Jyunichi Ohshima ◽

...

Keyword(s):

Principal Component Analysis ◽

Fibre Diameter ◽

Eucalyptus Camaldulensis ◽

Principal Component ◽

Wood Properties ◽

Component Analysis ◽

Pulp And Paper ◽

Anatomical Characteristics ◽

Diameter Fibre ◽

Sib Families

Sustainable pulpwood production from fast-growing tree plantations is needed for pulp and paper industries. To increase the pulpwood production efficiency, the anatomical characteristics and derived-wood properties of 75 trees from 15 half-sib families of Eucalyptus camaldulensis Dehnh. planted in Thailand were investigated, and then the family was classified by suitability of wood as raw material for pulp and paper products using principal component analysis and clustering. The mean values of vessel diameter, vessel frequency, fibre diameter, fibre lumen diameter, and fibre wall thickness at 2 cm from the cambium were 128 µm, 16 no./mm2, 11.1 µm, 7.1 µm, and 1.88 µm, respectively. In addition, the Runkel ratio, Luce’s shape factor, flexibility coefficient, slenderness ratio, solids factor, and wall coverage ratio (i.e., derived-wood properties) were 0.53, 0.42, 0.64, 85.3, 68 × 103 µm3, and 0.34, respectively. Significant differences in fibre diameter, fibre lumen diameter, and Runkel ratio were found among families. Although significant differences among families were not found for other anatomical characteristics and derived-wood properties, the p-values obtained by an analysis of variance test ranged from 0.050 to 0.088. Based on the results of a principal component analysis and cluster analysis, 15 families were classified into four clusters with different expected pulp and paper characteristics. The suitability of wood from E. camaldulensis half-sib families for pulp and paper can be evaluated by principal component analysis using anatomical characteristics and physical properties as variables. Based on the results, desirable pulp and paper quality may be obtained through the selection of families from this species.

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