Esterification of wood with citric acid: The catalytic effects of sodium hypophosphite (SHP)

Holzforschung ◽  
2014 ◽  
Vol 68 (4) ◽  
pp. 427-433 ◽  
Author(s):  
Xinhao Feng ◽  
Zefang Xiao ◽  
Shujuan Sui ◽  
Qingwen Wang ◽  
Yanjun Xie
Keyword(s):  
Citric Acid ◽  
Treated Wood ◽  
Wood Properties ◽  
Weight Percent ◽  
Point Of View ◽  
Modulus Of Rupture ◽  
Sodium Hypophosphite ◽  
Esterification Reaction ◽  
Water Leaching ◽  
Efficient Catalyst

Abstract Sodium hypophosphite (SHP) has been recognized as the most efficient catalyst in the esterification reaction of cellulosic fabrics with citric acid (CA), but both the high cost and the environmentally harmful property of SHP call for optimization of its application. In this study poplar wood (Populus adenopoda Maxim.) was treated with CA to various weight percent gains (WPGs) and the effect of SHP on the resulting properties of treated wood was investigated. Esterification with CA can occur also in the absence of SHP, as evidenced by the resistance to water leaching of CA. Wood treated with CA alone to 36% WPG exhibited 7% bulking, 50% anti-swelling efficiency, 30% reductions of the modulus of rupture, and 50% lower impact strength. Treatments with CA in the presence of SHP provided wood properties comparable to wood treated with CA alone. Thus the application of SHP can be questioned from the point of view of an economic production and environmental protection.

scholarly journals Furfural-based resin for modifying birch wood properties

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7139-7160
Author(s):  
Marzieh Sharifat ◽  
Davood Efhamisisi ◽  
Marie-France Thevenon ◽  
Asghar Tarmian ◽  
Mehdi Jonoobi
Keyword(s):  
Treated Wood ◽  
Weight Percent Gain ◽  
Wood Properties ◽  
Weight Percent ◽  
Modulus Of Rupture ◽  
Accelerated Weathering ◽  
Treatment Technology ◽  
Loaded Resin ◽  
Resin Curing ◽  
The Impact

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.

scholarly journals Response of Nano-Reinforced Cementitious Composites Using Natural and Commercial Dispersants

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 23
Author(s):  
Anwari ◽  
Khushnood ◽  
Ahmad ◽  
Muhammad ◽  
Tulliani
Keyword(s):  
Ultra Violet ◽  
Weight Percent ◽  
Point Of View ◽  
Modulus Of Rupture ◽  
Experimental Investigations ◽  
Early Age ◽  
Natural Surfactant ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

An efficient and promising approach from economy point of view to effectively disperse Multi-walled carbon nanotubes (MWCNTs) in cementitious environment has been devised. The natural organic extract from species of indigenously known ‘keekar’ trees scattered along tropical and sub-tropical countries; is found as an exceptional replacement to the non-natural commercial surfactant. In the initial phase ideal content of surfactant was explored in relation with the added content of MWCNTs using ultra-violet spectroscopy. The experimental investigations were then extended to five formulations containing 0.0, 0.025, 0.05, 0.08 and 0.10 MWCNTs by weight percent of cement. It was observed that the natural surfactant produced efficient dispersion at much reduced cost (>14% approx.) compared with the commercial alternate. The estimated weight efficiency factor ‘ϕ’ was found 6.5 times higher by the proposed sustainable replacement to the conventional with remarkable increase of 23% in modulus of rupture on 0.08 wt% addition of MWCNTs. Besides, strength enhancement the dispersed MWCNTs also improved the first crack and ultimate fracture toughness by 51.5% and 35.9%, respectively. The field emission scanning electron microscopy of the cryofractured samples revealed efficient dispersion of MWCNTs in the matrix leading to the phenomenon of effective crack bridging and crack branching in the composite matrix. Furthermore, the proposed scheme significantly reduced the early age volumetric shrinkage by 39% to mitigate early age micro-cracks encouraging long lasting deteriorations from durability prospects.

Radiata pine wood treatment with a dispersion of aqueous styrene/acrylic acid copolymer

Holzforschung ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 387-396 ◽  
Author(s):  
Wenbo Che ◽  
Zefang Xiao ◽  
Guanghui Han ◽  
Zhongguo Zheng ◽  
Yanjun Xie
Keyword(s):  
Acrylic Acid ◽  
Elevated Temperatures ◽  
Wood Quality ◽  
Surface Hardness ◽  
Treated Wood ◽  
Wood Properties ◽  
Weight Percent ◽  
Radiata Pine ◽  
Mechanical Reinforcement ◽  
The Impact

AbstractWood of radiata pine (Pinus radiataDon) was treated with an aqueous styrene/acrylic acid (St/AA) copolymer dispersion leading to weight percent gains (WPGs) of 10–42%. The reactivity of St/AA in wood and the modifying effects on wood properties were investigated. The St/AA precipitated in the cell lumens and condensed under catalysis at elevated temperatures was shown via scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Treatment did not cause positive bulking efficiency and anti-swelling efficiency, because St/AA cannot diffuse into the cell walls due to its high molecular mass. The modulus of elasticity and rupture (MOE and MOR, respectively), and the surface hardness of the wood were improved by 24.4, 22.2, and 40.6%, respectively. Compression strength increased by 81.6 and 48.2% in radial and longitudinal directions, but the impact strength was hardly influenced by the treatment. In addition, the treated wood was slightly more hydrophobic than untreated controls as shown by reduced moisture content and water uptake. Accordingly, treatment with St/AA leads to mechanical reinforcement of wood and enhances its water resistance, and as a consequence, it has an application potential to improve the wood quality.

Effect of a Polymer Additive on Properties of Creosote-Treated Wood

2019 ◽  
Vol 69 (1) ◽  
pp. 96-100
Author(s):  
Daniel B. Trebelhorn ◽  
Byrne Miyamoto ◽  
Jeffrey J. Morrell ◽  
Jeffrey Ellis ◽  
Stacey McKinney
Keyword(s):  
Modulus Of Elasticity ◽  
Elasticity Modulus ◽  
Treated Wood ◽  
Water Repellency ◽  
Wood Properties ◽  
Modulus Of Rupture ◽  
Low Molecular Weight ◽  
Moisture Uptake ◽  
Polymer Additive ◽  
The Impact

Abstract The potential for using a low molecular weight polyethylene (PE) polymer to improve the properties of creosote-treated wood was evaluated on samples of six different wood species. Samples were impregnated with creosote alone or amended with the PE additive and then tested to failure in third-point loading to determine modulus of elasticity and modulus of rupture. Samples were then subjected to three soak–dry cycles to assess the impact of moisture uptake on fastener performance or water repellency. The presence of the PE was associated with lower preservative retentions, but had no significant effect on modulus of elasticity, modulus of rupture, water repellency, or fastener withdrawal resistance. The results suggest that the additive limited preservative uptake, but did not improve any of the wood properties evaluated.

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.

scholarly journals Thermal, Physical and Mechanical Properties of Poly(Butylene Succinate)/Kenaf Core Fibers Composites Reinforced with Esterified Lignin

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2359
Author(s):  
Harmaen Ahmad Saffian ◽  
Masayuki Yamaguchi ◽  
Hidayah Ariffin ◽  
Khalina Abdan ◽  
Nur Kartinee Kassim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Loss Modulus ◽  
Physical And Mechanical Properties ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Esterification Reaction ◽  
Butylene Succinate ◽  
Kenaf Core ◽  
Modified Lignin

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.

Fabrication of highly stable and durable furfurylated wood materials. Part I: process optimization

Holzforschung ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 1135-1146
Author(s):  
Wanju Li ◽  
Minghui Liu ◽  
Hankun Wang ◽  
Yan Yu
Keyword(s):  
Orthogonal Experiment ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Chinese Fir ◽  
Curing Temperature ◽  
Modulus Of Rupture ◽  
Scale Production ◽  
Range Analysis ◽  
Decay Fungi ◽  
Mold Resistance

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.

Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material

2012 ◽  
Vol 576 ◽  
pp. 314-317
Author(s):  
Sinin Hamdan ◽  
M. Saiful Islam
Keyword(s):  
Mechanical Properties ◽  
Diazonium Salt ◽  
Treated Wood ◽  
Coupling Reaction ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Ft Ir ◽  
Ir Analysis ◽  
D Values ◽  
Benzene Diazonium

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

scholarly journals Pd/C Synthesized with Citric Acid: An Efficient Catalyst for Hydrogen Generation from Formic Acid/Sodium Formate

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Zhi-Li Wang ◽  
Jun-Min Yan ◽  
Hong-Li Wang ◽  
Yun Ping ◽  
Qing Jiang
Keyword(s):  
Citric Acid ◽  
Formic Acid ◽  
Hydrogen Generation ◽  
Sodium Formate ◽  
Efficient Catalyst

Study on Synthesis of Ester of Citric Acid and Palmityl Alcohol

2014 ◽  
Vol 900 ◽  
pp. 361-364
Author(s):  
Xiao Hui Wang ◽  
Xi Hua Du ◽  
Li Min Dong
Keyword(s):  
Reaction Time ◽  
Citric Acid ◽  
Cation Exchange ◽  
Sulfonic Acid ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Process Conditions ◽  
Toluene Sulfonic Acid

Esters of Citric acid and palmityl alcohol were synthesized by esterification reaction under catalysis of cation exchange resin and P-toluene sulfonic acid respectively. The effects of amount of catalyst, ratio of raw materials, reaction time and temperature on the synthesis reaction were investigated . The experimental results showed that optimum of process conditions were 1:1~1:1.5 molar ratio of citric acid and palmityl alcohol, reaction temperature of 130~140°C, reaction time of 2 h. Conversion of palmityl alcohol were all more than 90% under 0.3% dosage using p-toluene sulfonic acid as the catalyst, or 0.5% dosage using 721 cation exchange resin with sulfonic acid type as catalyst. The synthesized product had good surface activity.

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