scholarly journals Hydrophobization and Photo-Stabilization of Radiata Pinewood: The Effect of the Esterification on Thermal and Mechanical Properties

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1243
Author(s):  
René Herrera Díaz ◽  
Oihana Gordobil ◽  
Pedro L. de Hoyos-Martinez ◽  
Anna Sandak ◽  
Jalel Labidi

Wood protection through chemical modification has received increasing interest over the last decades due to the environmental issues related to conventional biocides or protecting products. Consequently, a wide range of new treatments are developed in laboratories, which are later scaled up in the industrial environment. The main goal of modifying wood for indoor–outdoor application is to change its hydrophilic character, which in turn improves the intrinsic properties of the material and its durability against external factors. Wood can be esterified through its hydroxyl groups to obtain a hydrophobic and photo-stable material. Chemical modifications of Pinus radiata D. Don wood using hexanoyl chloride (P6), dodecanoyl chloride (P12), and stearoyl chloride (P18) were carried out at different concentrations. Esterification was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) technique combined with a discriminatory analysis. Weight percent gain was associated with the number of carbons of the aliphatic chain of the fatty acid (P6 > P12 > P18). Moreover, an increase of wood density as a consequence of modification treatments was observed. A substantial improvement of the hydrophobicity of wood was observed by dynamic contact angle measurements. In addition, the effect of ultraviolet (UV) radiation on color changes was reduced with the treatments. Furthermore, the P6 treatment presented acceptable values of modulus of elasticity (MOE) and modulus of rupture (MOR), being suitable for similar mechanical uses as non-treated pinewood. However, only treatments P12 and P18 enhanced thermal resistance of the pinewood in an oxidative atmosphere.

Holzforschung ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 1135-1146
Author(s):  
Wanju Li ◽  
Minghui Liu ◽  
Hankun Wang ◽  
Yan Yu

AbstractIn order to improve dimensional stability and durability of wood, furfurylation of poplar and Chinese fir wood using newly developed furfuryl alcohol (FA) formulation combined with a common vacuum and pressure impregnation process was studied. An orthogonal experiment was designed to optimize the furfurylation process for the two wood species. The weight percent gain (WPG), equilibrium moisture content (EMC), anti-swelling efficiency (ASE), modulus of rupture (MOR), modulus of elasticity (MOE), as well as resistance to mold, decay fungi, and termites were evaluated. The results showed that nearly all the properties of the furfurylated wood could be improved to various extents. The average ASE of the furfurylated Chinese fir and poplar could reach as high as 80, 71, 92% and 79, 90, 75% in tangential and radial directions, and by volume, respectively, higher than most previously reported wood modification processes. Furthermore, the modified wood had excellent biological durability, with nearly 100% mold resistance, strong decay and termite resistance. Finally, processing parameters with 50% FA, 105–115 °C curing temperature, and 5–8 h curing time were therefore recommended for pilot-scale production of furfurylated poplar and Chinese fir wood based on range analysis.


2021 ◽  
Vol 891 (1) ◽  
pp. 012019
Author(s):  
I Rahayu ◽  
A Pratama ◽  
W Darmawan ◽  
D Nandika ◽  
E Prihatini

Abstract Abstract, Sengon (Falcataria moluccana Miq.) as a fast-growing wood species that has low quality. Therefore, wood modification is needed to improve its wood qualities. The objective of this study was to analyse the effect of monoethylene glycol (MEG) and nano silica of betung bamboo leaves impregnation treatment on physical, mechanical properties and durability of sengon wood. 5-years-old Sengon wood from community forest, MEG and nano silica (average size = 436.16 nm) from betung bamboo leaves were used. The impregnation solutions were consisted of water treated (untreated), MEG, MEGSilika 0.5% and MEGSilika 1%. Impregnation process with 0.5 bar (60 minutes) vacuum and 2.5 bar (120 minutes) pressure. Physical properties (density and colour alteration), mechanical properties (Modulus of Elasticity (MOE), Modulus of Rupture (MOR) and hardness) and durability against subterranean (Coptotermes curvignathus) attack. The results showed that the weight percent gain (WPG) and density of treated Sengon wood were increased as the nano silica concentration increased. While colour alteration (Δε) of treated samples were declining. Mechanical properties (MOE, MOR and hardness) were also improved. Durability based on laboratory tested against subterranean attack resulted that the percentage of termite mortality from the treated samples increased, while the percentage of weight loss decreased.


2021 ◽  
Vol 891 (1) ◽  
pp. 012014
Author(s):  
P A Sabrina ◽  
Y S Hadi ◽  
D S Nawawi ◽  
I B Abdillah ◽  
R Pari

Abstract Pine (Pinus merkusii Jungh. & de Vriese) and sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes) are common species of woods used for many purposes. Both species are known susceptible against subterranean termite attack. This study aims to analyze the effect of furfuryl alcohol impregnation on color changes and the resistance against subterranean termites of pinewood and sengon after in-ground test for one year. Furfurylated pine and sengon woods reached weight percent gain 31.2% and 79.1%, densities 0.93 g/cm3 and 0.43 g/cm3, moisture content 3.27% and 2.88%, respectively. Furfurylated pine and sengon woods have lost weight 4.07% dan 2.09%, respectively, with the average resistance level of 9.8 on both woods while untreated pine and sengon woods lost weight were 59.02% and 35.58%, with resistance level 4 and 3.8, respectively. Resistance level scoring was conducted by refering to ASTM D1758-06. Higher resistance level and lower weight loss on both furfurylated woods compared to untreated woods showed that furfurylation could increase the wood resistance against termite attack.


Holzforschung ◽  
2021 ◽  
Vol 75 (1) ◽  
pp. 83-90
Author(s):  
Christopher Ehrhardt ◽  
Marco Tapken ◽  
Jan C. Namyslo ◽  
Dieter E. Kaufmann

AbstractThe broad applicability of the wood modification protocol recently published by Kaufmann et al. allows to improve the fire resistance of renewable materials, too. In this study organophosphorus and organoboron compounds have been synthesized, characterized and subsequently applied for enhanced flame retardancy of wood. Wood hydroxyl groups of Scots pine (Pinus sylvestris L.) sapwood veneer chips were covalently modified upon esterification with benzotriazolyl-activated P- and B-substituted benz-amides. The efficacy of this synthetic strategy was demonstrated by the weight percent gain (WPG) of up to 32% and the corresponding quantities of covalently bonded organicmaterial (QCO) of up to 1.1 mmol/g, respectively. The successful covalent attachment of the functional precursors was proven by attenuated total reflection infrared spectroscopy (ATR-IR). The effect of the flame retardants on the properties of the modified sapwood samples was shown by a significant decrease of the temperature of mass loss from about 346–248 °C in the thermogravimetric analysis (TGA).


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7139-7160
Author(s):  
Marzieh Sharifat ◽  
Davood Efhamisisi ◽  
Marie-France Thevenon ◽  
Asghar Tarmian ◽  
Mehdi Jonoobi

Furfural (F) cannot be easily polymerized like furfuryl alcohol, but it is an aldehyde that can react with urea (U) to make a polymeric network. The possibility of preparing F/U polymer along with an acidic catalyzer (maleic anhydride; M) was evaluated as a means to improve some selected properties of birch (Betula pendula) wood. The F+U/M resin was introduced into the wood with a double treatment technology. The first step involved dilution of F in water and methanol, and the second step was immersion in a U/M aqueous solution. The color of treated wood was darkened after resin curing from brown to a spectrum of black depending on the amount of loaded resin. The 60 to 80% of materials were converted to a non-leachable polymer based on the different formulations. The water absorption and volumetric swelling of the treated samples decreased with an increase in weight percent gain (WPG). The analysis of mechanical strength showed that treatment with F + U/M reduced to some extent the hardness and the impact bending of wood, while modulus of rupture, modulus of elasticity, and compression parallel to the grain with WPG were increased. The exposure of the samples to the accelerated weathering showed noticeable changes in color and roughness.


Author(s):  
O.N Goncharova ◽  
◽  
I.V. Marchuk ◽  
A.V. Zakurdaeva ◽  
◽  
...  

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
MINAKSHI SERAWAT ◽  
V K PHOGAT ◽  
ANIL Abdul KAPOOR ◽  
VIJAY KANT SINGH ◽  
ASHA SERAWAT

Soil crust strength influences seedling emergence, penetration and morphology of plant roots, and, consequently, crop yields. A study was carried out to assess the role of different soil properties on crust strength atHisar, Haryana, India. The soil samples from 0-5 and 5-15 cm depths were collected from 21 locations from farmer’s fields, having a wide range of texture.Soil propertieswere evaluated in the laboratory and theirinfluence on the modulus of rupture (MOR), which is the measure of crust strength, was evaluated.The MOR of texturally different soils was significantly correlated with saturated hydraulic conductivity at both the depths. Dispersion ratio was found to decrease with an increase in fineness of the texture of soil and the lowest value was recorded in silty clay loam soil,which decreased with depth. The modulus of rupture was significantly negatively correlative with the dispersion ratio.There was no role of calcium carbonate in influencing the values of MOR of soils. Similarly,the influence of pH, EC and SAR of soil solution on MOR was non-significant.A perusal of thevalues of the correlations between MOR and different soil properties showed that the MOR of soils of Haryana are positively correlated with silt + clay (r = 0.805) followed by water-stable aggregates (r = 0.774), organic carbon (r = 0.738), silt (r = 0.711), mean weight diameter (r = 0.608) and clay (r = 0.593) while negatively correlated with dispersion ratio (r = - 0.872), sand (r = -0.801) and hydraulic conductivity (r = -0.752) of soils.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 32
Author(s):  
Xiaoshuang Shen ◽  
Pan Jiang ◽  
Dengkang Guo ◽  
Gaiyun Li ◽  
Fuxiang Chu ◽  
...  

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.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2359
Author(s):  
Harmaen Ahmad Saffian ◽  
Masayuki Yamaguchi ◽  
Hidayah Ariffin ◽  
Khalina Abdan ◽  
Nur Kartinee Kassim ◽  
...  

In this study, Kraft lignin was esterified with phthalic anhydride and was served as reinforcing filler for poly(butylene succinate) (PBS). Composites with different ratios of PBS, lignin (L), modified lignin (ML) and kenaf core fibers (KCF) were fabricated using a compounding method. The fabricated PBS composites and its counterparts were tested for thermal, physical and mechanical properties. Weight percent gain of 4.5% after lignin modification and the FTIR spectra has confirmed the occurrence of an esterification reaction. Better thermo-mechanical properties were observed in the PBS composites reinforced with modified lignin and KCF, as higher storage modulus and loss modulus were recorded using dynamic mechanical analysis. The density of the composites fabricated ranged from 1.26 to 1.43 g/cm3. Water absorption of the composites with the addition of modified lignin is higher than that of composites with unmodified lignin. Pure PBS exhibited the highest tensile strength of 18.62 MPa. Incorporation of lignin and KCF into PBS resulted in different extents of reduction in tensile strength (15.78 to 18.60 MPa). However, PBS composite reinforced with modified lignin exhibited better tensile and flexural strength compared to its unmodified lignin counterpart. PBS composite reinforced with 30 wt% ML and 20 wt% KCF had the highest Izod impact, as fibers could diverge the cracking propagation of the matrix. The thermal conductivity value of the composites ranged from 0.0903 to 0.0983 W/mK, showing great potential as a heat insulator.


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