The Analysis of Dimensional Changes Due to Chemical Treatments and Water Soaking for Hinoki (Chamaecyparis obtusa) Wood

Holzforschung ◽  
2002 ◽  
Vol 56 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Kosuke Ohmae ◽  
Kazuya Minato ◽  
Misato Norimoto
Keyword(s):  
Phenol Formaldehyde ◽  
Treated Wood ◽  
Untreated Wood ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Chamaecyparis Obtusa ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Dimensional Changes ◽  
Cell Lumen

Summary To clarify tangential and radial dimensional changes in hinoki (Chamaecyparis obtusa) wood by ten kinds of treatments and successive water soaking, a vector expression on the tangential-radial coordinates was proposed and a new measure (ASE′) to evaluate the dimensional stability of wood was defined. The ASE′ is expressed by 100(1 − Vs′ /Vu ) where Vu is the volumetric swelling coefficient of untreated wood and Vs′ is that of treated wood calculated on the basis of its oven-dried volume before treatment. The results from formaldehyde treated, heat treated and steam treated wood showed large positive ASE′ values and the ratio of radial swelling to tangential swelling (swelling anisotropy) of these treated woods decreased with increasing weight percent gain or weight loss. The results from acetylated wood, wood impregnated with polyethylene glycol and wood treated with a low molecular weight phenol-formaldehyde resin showed either small positive or negative ASE′ values, and those of wood treated with propylene oxide showed large negative values. The swelling anisotropy of treated woods accompanied by cell wall bulking was larger than that of untreated wood. The swelling anisotropy decreased when the cell lumen was filled with a hydrophobic resin (WPC-MMA), and increased when the cell lumen was filled with a hydrophilic resin (WPC-HEMA).

Effect of Technology Factors on the Resin Impregnation Results of Poplar

2013 ◽  
Vol 750-752 ◽  
pp. 2352-2356
Author(s):  
Jian Han ◽  
Kai Neng Liu ◽  
Xi Tao Gao
Keyword(s):  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Phenol Formaldehyde Resin ◽  
Solid Content ◽  
Formaldehyde Resin ◽  
Test Pieces ◽  
Resin Impregnation ◽  
Impregnation Temperature

Aimed to improve the properties of Poplar, this study, taking phenol-formaldehyde resin (PF) and urea-formaldehyde resin (UF) as impregnation resin, probed the effect of the technology factors-vacuum time, solid content of resin, impregnation temperature and time on the impregnation results of Poplar, and the relationship between the resin and the wood was researched through infrared spectrum. The weight percent gain (WPG) of test-pieces increased with vacuum time extending, and WPG of the test-pieces were greatest when the solid content of resin was 30%, and the impregnation temperature was 25-30°C. when the impregnation time extended from 3 h to 9 h, WPG of the test-pieces presented increase trend which wasnt obvious. In this wood impregnated resin, the reaction between the resin and the hydroxy in wood formed ether bond binding, which proved that the resin and the wood occurred the chemical reaction.

Evaluation of water related properties of birch wood products modified with different molecular weight phenol-formaldehyde oligomers

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Juris Grinins ◽  
Vladimirs Biziks ◽  
Janis Rizikovs ◽  
Ilze Irbe ◽  
Holger Militz
Keyword(s):  
Molecular Weight ◽  
Dimensional Stability ◽  
Phenol Formaldehyde ◽  
Treated Wood ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Solid Wood ◽  
Wood Products ◽  
Birch Wood ◽  
Molecular Weights

Abstract This study investigated the effect of phenol-formaldehyde (PF) resin treatment on the dimensional stability of birch solid wood and plywood. Therefore, three different low molecular weight PF resins with average molecular weights (M w ) of 292, 528, and 884 g/mol were synthesized and used for silver birch (Betula pendula) solid wood (20 × 20 × 20 mm3) and veneer (100 × 100 × 1.4 and 300 × 300 × 1.4 mm3) impregnation to produce plywood. The weight percent gain (WPG) and bulking after curing of resin treated wood specimens were determined. The leaching was performed to evaluate the PF resin fixation stability. All tested resins at all concentrations were similarly fixed in wood blocks after the leaching (1.5–2.0% WPG loss). The dimensional stability of birch wood after treatment with all tested PF resins was significantly improved. The anti-swelling efficiency (ASE) of birch wood blocks treated with PF resins after seven water soaking-drying cycles was in the range of 39–53%, 46–65% and 49–65% using 10, 15 and 20% solution concentrations, respectively. Whereas, the ASE of plywood obtained from veneers treated with 10% of PF solution was improved by 6–20%. The equilibrium moisture content (EMC) and volumetric swelling (VS) of PF treated plywood at 98% of relative humidity (RH) decreased significantly. All PF resin treated plywood surfaces were more hydrophobic compared to untreated plywood.

Suitability of a lignin-derived mono-phenol mimic to replace phenol in phenol-formaldehyde resin for use in wood treatment

Holzforschung ◽  
2020 ◽  
Vol 74 (4) ◽  
pp. 344-350
Author(s):  
Vladimirs Biziks ◽  
Marco Fleckenstein ◽  
Carsten Mai ◽  
Holger Militz
Keyword(s):  
Phenol Formaldehyde ◽  
Average Molecular Weight ◽  
Treated Wood ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Pyrolysis Oil ◽  
Scanning Calorimetry ◽  
Wood Treatment ◽  
Aromatic Derivative ◽  
Bio Oil

AbstractThe goal of this study was to assess the suitability of a single mono-aromatic for substitution of petroleum-based phenol for phenol-formaldehyde (PF) resin synthesis and the usage of a new resin for wood treatment. After proper thermal decomposition of wood-based lignin, pyrolysis oil can be obtained. Due to the heterogeneity of the lignin macromolecule, oil contains large variety of organic-based compounds, mainly mono-aromatics, which are proposed to be used for replacement of phenol during PF resin synthesis. Therefore, for this purpose, nine of the most abundant mono-aromatic compounds in bio-oil were selected: ortho-, meta-, para-cresol, guaiacol, catechol, 4-methylcatechol, resorcinol, syringol, 4-ethylphenol and resol-type resin from each mono-aromatic were synthesized. Relevant features of the resin such as pH, viscosity, average molecular weight and curing behavior of resins using differential scanning calorimetry (DSC) were analyzed. Scots pine (Pinus sylvestris L.) sapwood samples were used to evaluate the suitability of resin for wood treatment in terms of dimensional stability and were compared with the PF resin-treated wood. From all tested resins, those made of guaiacol or ortho-, or meta-, or para-cresol and/or 4-ethylphenol proved to be suitable for wood treatment, whereas resins made of catechol or 4-methylguaiacol and syringol did not. Suitability of mono-aromatics for synthesis of resol-type resin depends on chemical structure, where the reactivity of the mono-aromatic (derivative of hydroxybenzene) is defined by the type, location and number of substituents.

Water Related Properties of Birch Wood Modified with Phenol-Formaldehyde (PF) Resins

2019 ◽  
Vol 800 ◽  
pp. 246-250
Author(s):  
Juris Grinins ◽  
Vladimirs Biziks ◽  
Ilze Irbe ◽  
Janis Rizhikovs
Keyword(s):  
Phenol Formaldehyde ◽  
Treated Wood ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Solid Wood ◽  
Specimen Size ◽  
Fixation Stability ◽  
Resin Loading ◽  
The Impact ◽  
Leaching Procedure

In this study, Silver birch (Betula pendula) wood veneers and solid wood blocks were treated with commercial phenol-formaldehyde (PF) resin water solutions. Birch veneers and solid wood blocks of different size were impregnated with PF resin solutions in water with concentrations of 10, 20 and 30 wt%. The weight percent gain (WPG) and bulking after drying and curing of resin treated wood specimens were determined to evaluate the impact of specimen sizes and density. The leaching procedure according to EN 84 was performed to evaluate the PF resin fixation stability. The anti-swelling efficiency (ASE) of untreated and treated specimens during seven soaking-drying cycles was examined. Higher WPG values were obtained for specimens with lower density, but no correlation was found between the specimen size and WPG. The WPG of veneers and solid wood was 8.7 - 17.7% and 8.5 - 24.4%, respectively. The ASE of wood blocks treated with PF resins after the 1st cycle was in the range of 37 - 51% depending on the resin loading in the wood. However, the ASE values decreased after every next soaking-drying cycle, reaching 33 - 48% after the 7th cycle. After leaching, the WPG of specimens decreased by 2.3 - 3.0%.

Purification of water contaminated with heavy metals by example of lead as promising material based on graphene nanostructures

2020 ◽  
pp. 34-43
Author(s):  
N. R. Memetov ◽  
◽  
A. V. Gerasimova ◽  
A. E. Kucherova ◽  
◽  
...  
Keyword(s):  
Adsorption Process ◽  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Parameter Estimates ◽  
Maximum Adsorption Capacity ◽  
Ecological Situation ◽  
Characteristic Parameters ◽  
Purification Of Water ◽  
Graphene Nanostructures

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.

scholarly journals Effect of Furfurylation on Hierarchical Porous Structure of Poplar Wood

Polymers ◽  
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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