Weight Percent Gain Research Articles

Adhesion performance of furfurylated plywood bonded with polyurethane and epoxy adhesives

Utilizing furfurylated veneers to improve the quality of plywood has not been extensively studied before. This study investigated the characteristics of plywood made from furfurylated rubberwood (Hevea brasiliensis) veneers at various modification levels. Rubberwood veneers were first impregnated with furfuryl alcohol (FA) at different concentrations (40%, 70%, and 100%) with 3% citric acid as a catalyst for FA polymerization at 103 °C. The weight percent gain (WPG), dynamic mechanical analysis (DMA), and functional groups of the furfurylated veneers were analyzed. The furfurylated veneers were then used to form three layers of plywood using either polyurethane (PU) or epoxy resin as the adhesive. Various physical, mechanical, and morphological properties of the furfurylated plywood were characterized. The WPG of the veneers impregnated with 40%, 70%, and 100% FA were on average 32.2%, 54.1%, and 67.9%, respectively. DMA and ATR-FTIR analyses revealed differences between the control veneers and the furfurylated veneers. Furfurylation slightly decreased the bonding strength of PU-bonded plywood at 100% FA, while the epoxy-bonded plywood remained unchanged at all FA concentrations. Furfurylation reduced the delamination values of plywood, particularly for treatments with 40% and 100% FA. Moreover, the use of 100% FA reduced the thickness swelling, water absorption, and leaching values of the plywood after seven days of water immersion by 43.6%, 73.9%, and 73.8% with PU adhesive, and by 85.7%, 69.6%, and 80.2% with epoxy adhesive, respectively. The formation of furfurylated plywood in this study opens potential opportunities for using low-quality veneers from fast-growing wood species as substitutes for high-quality veneers from natural forests.

Fixation of Tripotassium Citrate Flame Retardant Using a Sorbitol and Citric Acid Wood-Modification Treatment.

Wood modification has been explored in various ways to enhance dimensional stability and reduce flammability, with a focus on environmentally friendly treatments to meet market demands. This study aimed to investigate the efficacy of new, potential fire-retardant materials. Specifically, the study examined the combination of tripotassium citrate (TPC), a water-soluble and bio-based fire retardant, with sorbitol and citric acid (SorCA), an eco-friendly thermosetting resin previously studied. While TPC is known to control combustion, its application in wood modification has not been thoroughly researched. To assess the fixation and flammability of these fire retardants, tests were conducted on Scots Pine (Pinus sylvestris L.), including chemical analysis, dimensional stability, mechanical properties, flame retardancy, and leaching tests. The combination of SorCA and TPC showed high weight percent gain (WPG) values; however, leaching and anti-swelling efficiency (ASE) tests revealed challenges in fixation stability. The dynamic mechanical properties were reduced, whereas the static strength values were in the same range compared with untreated wood. While TPC exhibited high flame retardancy prior to leaching, its efficacy diminished post-leaching, underscoring challenges in fixation and the need for improved retention strategies. Bunsen burner tests conducted on leached specimens indicated enhanced performance even under severe leaching conditions as per the EN 84:2020 procedure. However, cone calorimetry measurements showed less favorable outcomes, emphasizing the necessity for further investigation into optimizing TPC retention and enhancing treatment efficacy.

Eco-friendly flame retardant comprising chitosan-based effectively enhances the flame retardancy of wood with low weight percent gain

Nowadays, there are many types of flame retardants, whether halogenated or halogen-free, that can improve the flame retardancy of wood. However, they continue to pose a significant threat to our environment and cause a substantial increase in the weight gain rates after treatment. It is highly desirable yet challenging to develop an eco-friendly and efficient flame retardant with low weight gain rates. Here, we report a simple and fast process for making eco-friendly flame retardants (chitosan, gelatin, sodium phytate and clay) with weight gain rates of 3.7 %, which form excellent flame retardancy systems. This method can be used to create a 53.5 % reduction in peak heat release rate (pHRR) an 189 % increase in ignition time (cone colorimeter), and a 71.9 % reduction in peak temperature (alcohol spray lamps) compared to raw wood. The results displayed that the effect of flame retardancy (Decreased ratio for pHRR/Weight percent gain) was the best in the past three years. In addition, the flame retardancy mechanism is thoroughly analyzed using the techniques of Raman and so on. This study proposes a novel strategy featured by eco-friendly and simple preparation process for enhancing the flame retardancy of wood in important areas.

Effectiveness Evaluation of Silicone Oil Emulsion In Situ Polymerization for Dehydration of Waterlogged Wooden Artifacts

Organosilicon materials have shown potential as dehydration agents for waterlogged wooden artifacts. These materials can polymerize under normal conditions to form polymers with favorable mechanical strength, antibacterial properties, and aging resistance. However, the insolubility of most organosilicon hindered their penetration into waterlogged wood, which may lead to an unwanted cracking. This study aimed to evaluate the effectiveness of polydimethylsiloxane (PDMS) and hydroxy-terminated polydimethylsiloxane (PDMS-OH) with low viscosity and moderate reactivity for dehydrating waterlogged wooden artifacts from the Nanhai No.1 shipwreck. Four surfactants ((3–aminopropyl) triethoxysilane (APTES), alkyl polyoxyethylene ether (APEO), tri-methylstearylammonium chloride (STAC), and fatty alcohol polyoxyethylene ether (AEO)) and cosurfactant were employed to transform the two kinds of water-repellent silicone oils into eight groups of highly permeable oil-in-water (O/W) emulsions. Under the catalysis of a neutral catalyst, in situ polymerization occurred within the wood cells. Group P2-2 formulated with PDMS-OH and APEO showed the best efficiency in maintaining the dimensions of the wood during dehydration. The dehydrated wood exhibited a natural color and texture with a minimal volume shrinkage rate of 1.89%. The resulting polymer adhered uniformly to the cell walls, effectively reinforcing the wood cell structure. The weight percent gain of the wood was only 218%, and the pores of the cell lumen were well maintained for future retreatment. This method effectively controlled the sol–gel reaction process of the organosilicon and prevented damage to the wooden artifact during the dehydration process. Moreover, the dehydrated wood samples only experienced a low weight gain of 17% at 95% relative humidity (RH), indicating their great environmental stability.

Precise cell wall modification of bamboo through two-step furfurylation via solution quantitative adsorption

Improving the dimensional stability of bamboo for construction and engineering use through furfurylation is crucial. Traditional methods like impregnation and soaking furfurylation are hindered by high modifier consumption and waste disposal issues. In this study, we propose a novel technique called solution quantitative adsorption furfurylation (SQAF) to enhance bamboo's dimensional stability and overcome these challenges. Our findings indicate that SQAF achieves enhanced dimensional stability (anti-swelling efficiency (ASE) up to 53.02 %) and reduced hygroscopicity (EMC down to 4.11 %) with approximately 12.50 % weight percentage gain (WPG), and a high furfuryl alcohol (FA) utilization efficiency (SR > 85 %). Analysis using SEM and nanoindentation reveals precise modification of the cell walls without FA resin accumulating in cell cavities. Additionally, SQAF allows for a graded distribution of FA resin, thereby improving the physical properties of bamboo while maintaining its mechanical integrity, especially as the decline in toughness of bamboo is reduced by more than 40 % compared to traditional methods.

Impregnation Effect of Synthesized Fe3O4 Nanoparticles on the Jabon Wood’s Physical Properties

This study focused on characterizing synthetic magnetite (Fe3O4-NP) and evaluating the impregnated jabon wood’s physical properties. The co-precipitation method used for the synthesis of Fe3O4-NP, namely by mixing the iron solution (n/n Fe2+:Fe3+=1:2) with the strong base of sodium hydroxide (NaOH) (MG-S) and weak base of ammonium hydroxide (NH4OH) (MG-W) as precursors. The impregnation stage uses parameters of a -0.5 bar vacuum for half an hour and 2 bar pressure for 2 hours with magnetite concentrations of 1; 2.5; 5% w/v in a demineralized water solvent. Scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX) and Fourier transform infrared spectrometry (FTIR) confirmed the presence of Ferrum content and Fe-O functional group in both Fe3O4-NPs produced. The Fe3O4-NP size was also measured via the X-ray diffraction analysis, namely 34.54 nm for the MG-S and 39.24 nm for the MG-W. Magnetic strength obtained was 7.51 mT for the MG-S and 8.58 mT for the MG-W. The impregnated jabon wood’s physical properties also improved with indications of an increase in wood density, weight percent gain (WPG), bulking effect (BE), anti-swelling efficiency (ASE), and a decrease in water absorption (WA). The results showed the best treatments were MG-S 2.5% and MG-W 5%.

Mikrostruktur dan Karakteristik Permukaan Kayu Pinus Scots (Pinus sylvestris L.) Termodifikasi Gliserol dan Asam Sitrat

Scots pine (Pinus sylvestris L.) wood is one of the most popular timber export products. However, its low durability can reduce the potential and utilization of the wood. Chemical modification is one of the solutions to overcome this drawback. Chemical modification using non-biocide materials such as glycerol and citric acid was carried out to improve the inferior properties of wood. The study aimed to observe the microstructure and evaluate the surface characteristics of glycerol and citric acid-modified scots pine wood. Scots pine wood was modified using glycerol and citric acid with weight percent gain (WPG) values of 20% and 46%. Surface characteristics were measured, including surface roughness, surface free energy (SFE), wettability, and bonding quality. The results show that chemical modification using glycerol and citric acid resulted in the structure of the pine wood being more filled and denser. The modification could also reduce the roughness of the wood surface, resulting in decreased SFE value, increased contact angle, and decreased wettability on the wood surface. It might cause a decrease in the bonding quality because the wood did not have the strength to mechanically lock with the paint. Glycerol and citric acid modified-scots pine wood can be considered for exterior application. Keywords: citric acid, glycerol, microstructure, scots pine, surface characteristics

Cell Wall Modification Based on Combination Reagents to Improve Dimensional Stability of Wood with High Efficiency.

Although γ-methacryloxypropyltrimethoxysilane (MPS) was proved to be an effective reagent for improving the dimensional stability of wood, a bottleneck in ASE value (around 50%) existed. The reason was that MPS with low polarity opened few hydrogen bonds in the amorphous region of cellulose, while these hydrogen bonds could be reopened by water. Therefore, citric acid (CA) is chosen to cooperate with MPS to further enhance the dimensional stability of wood. In this paper, MPS and CA were used to modify wood individually (MW and CW) or with different combinations, that is, one-step modification (M/CW) and two-step modification with MPS first (M-CW) or CA first (C-MW). CA and MPS concentrations were optimized at 5 wt%. The ASE value for M/CW was only 25.74% at a weight percent gain (WPG) of 6.43%, which was only 0.6 times to MW or 0.7 times to CW. For M-CW, the ASE value gradually decreased with the soaking cycles, from 65.64% at a WPG of 9.05% to 51.20%. The C-MW had the best dimensional stability, with the ASE value 75.35% at a WPG of 11.50%. Although it decreased during the first soaking cycle, it stabilized at 62.20% at last. SEM and EDS images showed that the polymer mainly distributed in cell walls and few in cell lumen in C-MW. Thus, the enhanced dimensional stability of C-MW could be explained by CA opening the hydrogen bonds in the amorphous region of cellulose first, which provided more binding sites for MPS.

Decay and Termite Resistance of Wood Modified by High-Temperature Vapour-Phase Acetylation (HTVPA), a Simultaneous Acetylation and Heat Treatment Modification Process.

High-temperature vapour-phase acetylation (HTVPA) is a simultaneous acetylation and heat treatment process for wood modification. This study was the first investigation into the impact of HTVPA treatment on the resistance of wood to biological degradation. In the termite resistance test, untreated wood exhibited a mass loss (MLt) of 20.3%, while HTVPA-modified wood showed a reduced MLt of 6.6-3.2%, which decreased with an increase in weight percent gain (WPG), and the termite mortality reached 95-100%. Furthermore, after a 12-week decay resistance test against brown-rot fungi (Laetiporus sulfureus and Fomitopsis pinicola), untreated wood exhibited mass loss (MLd) values of 39.6% and 54.5%, respectively, while HTVPA-modified wood exhibited MLd values of 0.2-0.9% and -0.2-0.3%, respectively, with no significant influence from WPG. Similar results were observed in decay resistance tests against white-rot fungi (Lenzites betulina and Trametes versicolor). The results of this study demonstrated that HTVPA treatment not only effectively enhanced the decay resistance of wood but also offered superior enhancement relative to separate heat treatment or acetylation processes. In addition, all the HTVPA-modified wood specimens prepared in this study met the requirements of the CNS 6717 wood preservative standard, with an MLd of less than 3% for decay-resistant materials.

Improvement of physical and mechanical properties of belangke bamboo (Gigantochloa pruriens) laminated boards using boric acid immersion

A laminate board is a composite board formed from a combination of several laminates and glued together using adhesives in the parallel direction of the fibers. Belangke bamboo, as a substitute for wood, can be used as raw material for making laminated boards. Belangke bamboo has fairly good strength but has a weakness, namely, being vulnerable to attacks by destructive agents. Adding boric acid immersion treatment is one of the modifications to laminated boards to increase their strength and durability against attacks by destructive organisms. This study aims to analyze the physical and mechanical properties of laminated boards from striped bamboo with the effect of immersion treatment from 0 hours, 6 hours, 12 hours and 24 hours. The laminated board consists of 3 layers measuring 30 cm long, 15 cm wide, and 0.5 cm thick, which are glued using 280 g/m2 isocyanate adhesive and cold pressed for 24 hours with conditioning for ten days. The results of the physical properties test of this study obtained the average value in the weight percent gain (WPG) test ranged from 2.66-3.33%, density ranged from 0.79-0.97 g/cm3, moisture content ranged from 12.67%-13.40%, and delamination ranged from 2.37-7.77%. The results of mechanical properties testing showed the average value of modulus of elasticity (MOE) testing of 112383.20-127377.74 kg/cm2, modulus of rupture (MOR) of 371.69-578.95 kg/cm2, and shear strength ranged from 14.61–27.73 kg/cm2. From the analysis of variance, the best-laminated board is found in the 6-hour boric acid immersion time.

Physical and mechanical properties of belangke (Gigantochloa pruriens) bamboo laminated boards modified with citric acid

Belangke bamboo can be used to produce laminated boards due to its good mechanical properties. This study investigates the physical and mechanical properties of laminated boards from belangke bamboo at various immersion times of citric acid. Bamboo lamina is arranged into laminated boards (3 layers of bamboo lamina) with dimensions of 30 x 15 x 1.5 cm (Length x Width x Thickness). Laminated boards were glued using isocyanate adhesive with glue spread level of 280 g/m2. Testing of this laminated board includes physical and mechanical properties. Testing of physical properties, including weight percent gain (WPG), density, moisture content (MC), and delamination. Meanwhile, mechanical properties include modulus of elasticity (MOE), modulus of rupture (MOR), and shear strength. The physical and mechanical properties of belangke bamboo laminated in this study resulted in WPG values ranging from 7.00-10.00%, density with a range of 0.79–0.86 g/cm3, moisture content with a range of 11.86-12.67%, delamination ranged from 0.00-7.77%, MOE ranged from 113686-127378 kg/cm2, MOR ranged from 516.97–578.95 kg/cm2, and shear strength ranged from 20.53–27.73 kg/cm2. The best of the physical and mechanical properties of citric acid-modified belangke laminated boards in this study were laminated boards with 24-hour immersion time

The Effect of Synthetic and Commercial Nano-Magnetite on the Electromagnetic Absorbance Behavior of Magnetic Wood

Magnetic wood with good electromagnetic wave absorption properties was prepared by comparing synthetic and commercial nano-magnetite (Fe3O4-NP) as sengon (Falcataria moluccana) wood impregnation solution. The co-precipitation method produced a synthetic nano-magnetite with NH4OH as a weak base precursor. Meanwhile, the commercial one was purchased from a supplier. Three levels of nano-magnetite concentration (1%, 2.5%, and 5%) were dispersed in deionized water. The impregnation process was done by applying a vacuum of 0.5 bar for 120 minutes, followed by a pressure of 1 bar for 120 minutes. The results showed that the commercial nano-magnetite caused more improvements in weight percent gain, density, and hardness than the synthetic nano-magnetic, although they were insignificantly different. There was also a reduction in brightness with the overall color change being categorized into other colors because the color became darker with increasing nano-magnetite concentration in both woods. The absorbance capacity of the synthetic nano-magnetite-treated wood was larger than the commercial nano-magnetite-treated wood. This synthetic nano-magnetite-treated wood had been optimally treated at a 5% concentration, making it suitable for use as electromagnetic wave shielding material because it can absorb almost 100% electromagnetic waves. Keywords: Fe3O4, impregnation, nano-magnetite, sengon wood, shielding materials

Resistance against fungal decay of Scots pine sapwood modified with phenol-formaldehyde resins with substitution of phenol by lignin pyrolysis products

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.

Effects of the combination of phenolic-resin impregnation and heat treatment on physical, mechanical and decay resistance of Taxodium hybrid “Zhongshanshan” wood

ABSTRACT This study aimed to evaluate the influence of cooperative modification treatments and treatment sequencing on the properties of treated fast-growing wood. Two integrated treatment methods including, impregnation with Phenol-Formaldehyde resin followed by heat treatment (PF-HT), and heat treatment antecedent to impregnation with Phenol-Formaldehyde resin (HT-PF) were applied on Taxodium hybrid “Zhongshanshan” wood. Comprehensive characterization was undertaken, investigating micro-morphology, chemical structure, mechanical properties, shrinkage and expansion properties, and decay resistance before and after treatment. Results indicated that the weight percentage gain (WPG) of the HT-PF wood exceeded that of the PF-HT wood, and the WPG of the former displayed an ascending tendency with increasing heating temperature, reaching a final difference of 10%. For instance, the modulus of elasticity of the HT-PF wood was 18% higher than that of the PF-HT wood in the bending test at a temperature of 215°C. Throughout the dynamic water adsorption test, both the hydrated water percentage and the dissolved water percentage of PF-HT wood were lower than those of PF-HT wood. After 3 months of exposure to brown-rot fungi, both HT-PF wood and PF-HT wood achieved a high level of decay resistance.

Development of an index that decreases birth weight, promotes postnatal growth and yet minimizes selection intensity in beef cattle.

The main goal of our current study was to improve the growth curve of meat animals by decreasing the birth weight while achieving a finishing weight that is the same as that before selection but at younger age. Random regression model was developed to derive various selection indices to achieve desired gains in body weight at target time points throughout the fattening process. We considered absolute and proportional gains at specific ages (in weeks) and for various stages (i.e., early, middle, late) during the fattening process. The point gain index was particularly easy to use because breeders can assign a specific age (in weeks) as a time point and model either the actual weight gain desired or a scaled percentage gain in body weight. The point gain index we developed can achieve the desired weight gain at any given postnatal week of the growing process and is an easy-to-use and practical option for improving the growth curve.

Chemical Composition and FTIR Analysis of Acetylated Turkey Oak and Pannonia Poplar Wood

In this research, acetylation was applied under industrial conditions to improve the properties of Turkey oak and Pannonia poplar wood. Both species are potential “climate winners” in Hungary, yet they are currently underused due their low durability and poor dimensional stability. The acetylation modification process may be a suitable method to improve their properties. In order to verify the effectiveness of the process, comparative chemical analyses (cellulose, hemicelluloses, lignin, extractives, ash, buffering capacity, and pH) of the untreated and acetylated heartwood and sapwood were carried out for both species for the first time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was also used to support the evaluation of the chemical analyses. The weight percent gain was 11.54% for poplar and 0.94% for Turkey oak, indicating poor treatment efficiency for the latter. The cellulose, hemicelluloses, and lignin contents changed significantly in poplar, with the highest change (+81%) induced by acetylating the hemicelluloses. Only the alpha-cellulose content decreased significantly in Turkey oak, presumably due to the degradation of the non-crystalline part of the cellulose. Acetylation may improve the resistance of Pannonia poplar against moisture, weather, decay, and wood-boring insects, but the process parameters need to be optimized in order to prevent degradation and discoloration in poplar. Turkey oak was found to be less suitable for acetylation due to its low permeability and tendency to crack.

A new strategy for the preparation of wood-epoxy resin composites reinforced with controllable osmotic interfaces

As a multifunctional material, wood is widely used in interior decoration and construction engineering. The full-cell process of impregnating monomers into wood pores cavity in situ is one of the most common wood modification methods. However, this approach is time-consuming, material-wasting, and not environmentally friendly. In this study, we proposed a simple strategy to directly convert wood into high-performance composites by controlling wood surface penetration through resin pre-curing. A slight amount of resin used was sufficient to penetrate the wood surfaces, and the weight percent gain (WPG) of 11.45 %. High energy efficiency was achieved by simple temperature control (60 °C/120 °C). In addition, this method can rapidly produce wood composites with ultra-low density (0.51 g/cm3) and ultra-high specific bending strength (284 MPa·cm3g−1) in a very short time (4 h and 30 min). The results showed that the problem of excessive resin penetration was effectively solved by the pre-curing process, which enriched the gradient distribution of resin from the surface to the bottom of the wood and significantly improved the material properties. This efficient and environmentally friendly preparation strategy makes natural wood a low-cost, low-density, high-strength engineering material, which broadens the application of wood composites in construction engineering and interior decoration.

Bio‐based phase change material for enhanced building energy efficiency: A study of beech and thermally modified beech wood for wall structures

AbstractThis study investigated the impregnation of beech and thermally modified beech (TMB) with a ternary mixture of capric acid, palmitic acid, and stearic acid as a bio‐based phase change material (BPCM). Finite element method (FEM) was used to complement the experimental analysis by providing new insights into computational methods for simulating the behavior of BPCMs in untreated and TMB. The analyzed specimens namely beech and TMB were impregnated with BPCM; the TMB achieved 54% weight percentage gain (WPG) while untreated beech got 37%. Accordingly, a greater increase in the latent heat was obtained for TMB up to 90 J/g, while for untreated beech with BPCM up to 75 J/g. Impregnated specimens absorbed less moisture at relative humidity of air above 50%, likely caused by the high uptake and hydrophobic nature of the BPCM. The study highlights the research gap in performing mathematical simulations on wood samples with BPCM using material thermal properties derived from differential scanning calorimetry or T‐History analysis. It shows that the direct use of these values for simulations leads to unacceptable outputs that result in high errors. The root mean square error for untreated and TMB samples impregnated with BPCM was in the range from 1.06 to 3.1 while that for untreated samples was in the range from 0.57 to 0.87, indicating that the main challenge in simulating and characterizing the samples is due to the interaction of the phase change material with the wood structure.

Revealing the behavior and mechanism of surfactant-assisted liquid permeability in Poplar wood

Wood is a sustainable and porous resource that can be utilized to fabricate advanced functional materials. However, the low permeability of liquids within wood poses a challenge to widespread adoption and implementation of technology for producing wood-based functional materials. Surfactants are capable of reducing surface tension of liquids, thus holding promise for enhancing liquid permeability in wood. The effect of four surfactants (JFC-U, Tween 80, OP-10, DDAC) on liquid absorption of copper ethanolamine (CE) in wood was investigated under room temperature and pressure. Surfactants effectively increased liquid absorption of wood up to 2.3 times and weight percent gain by up to 5.8 times compared with that of CE control. The improvement effect of surfactants resulted from three aspects: significantly improved liquid wetting on wood surface, enhanced penetration of liquid in cell lumen, and promoted molecular movement within cell wall. Their contributions varied with the structure of surfactants. Surfactants with linear structure showing significantly reduced surface tension, and cationic surfactants exhibiting high adsorption capacity on wood surface both demonstrated superior efficacy in increasing liquid permeability. This study explored the mechanisms by which surfactants affect liquid permeability within wood, while also provided guidance to select effective surfactants to assist wood impregnation.

Enhancement of mechanical and flame-retardant properties of Acacia hybrid through the treatment of a combination of styrene-acrylic copolymer and sodium silicate

The mechanical and flame-retardant properties of Acacia hybrid wood were studied through the treatment of an aqueous solution containing a styrene-acrylic copolymer (SC) and sodium silicate (SS). The results showed a significant increase in the mechanical properties of SC/SS-treated wood. Specifically, the modulus of rupture (MOR) and modulus of elasticity (MOE) improved by up to 71.54% and 53.65%, respectively. The surface hardness of the cross-section and radial section also increased by 37.24% and 46.65%, respectively. The treated wood’s weight percentage gain (WPG) reached up to 23.31%. The largest leaching rate (LR) of treated wood was only 8.01%, suggesting this treatment has obvious effects in fixing the SS in the wood. However, it did not cause positive bulking efficiency (BE) and anti-swelling efficiency (ASE). The incorporation of SS with SC resulted in the decomposition of polysaccharides at a lower temperature while increasing the limiting oxygen index (LOI), which was 34.95% higher than that of untreated wood, making it more difficult to ignite. Scanning electron microscopy (SEM) results showed that the SC/SS deposited in the cell lumina after polymerization, but significant structural changes occurred, including vessel and cell wall deformation due to the partial dissolution of hemicellulose and lignin from the cell wall in the alkaline solution. The results of this study demonstrate the feasibility of applying the SC/SS combination treatment to wood in practical applications.