Cell Wall Bulking by Maleic Anhydride for Wood Durability Improvement

Wood is susceptible to swelling deformation and decay fungi due to moisture adsorption that originates from the dynamic nanopores of the cell wall and the abundant hydroxyl groups in wood components. This study employed as a modifier maleic anhydride (MAn), with the help of acetone as solvent, to diffuse into the wood cell wall, bulk nanopores, and further chemically bond to the hydroxyl groups of wood components, reducing the numbers of free hydroxyl groups and weakening the diffusion of water molecules into the wood cell wall. The derived MAn-bulked wood, compared to the control wood, presented a reduction in water absorptivity (RWA) of ~23% as well as an anti-swelling efficiency (ASE) of ~39% after immersion in water for 228 h, and showed an improvement in decay resistance of 81.42% against white-rot fungus and 69.79% against brown-rot fungus, respectively. The method of combined cell wall bulking and hydroxyl group bonding could effectively improve the dimensional stability and decay resistance with lower doses of modifier, providing a new strategy for wood durability improvement.

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Mode of action of brown rot decay resistance in modified wood: a review

Holzforschung ◽

10.1515/hf-2013-0057 ◽

2014 ◽

Vol 68 (2) ◽

pp. 239-246 ◽

Cited By ~ 66

Author(s):

Rebecka Ringman ◽

Annica Pilgård ◽

Christian Brischke ◽

Klaus Richter

Keyword(s):

Cell Wall ◽

Mode Of Action ◽

Wood Decay ◽

Brown Rot ◽

Decay Resistance ◽

Hydroxyl Groups ◽

Decay Fungi ◽

Brown Rot Decay ◽

Thermally Modified Wood ◽

Modified Wood

Abstract Chemically or physically modified wood materials have enhanced resistance to wood decay fungi. In contrast to treatments with traditional wood preservatives, where the resistance is caused mainly by the toxicity of the chemicals added, little is known about the mode of action of nontoxic wood modification methods. This study reviews established theories related to resistance in acetylated, furfurylated, dimethylol dihydroxyethyleneurea-treated, and thermally modified wood. The main conclusion is that only one theory provides a consistent explanation for the initial inhibition of brown rot degradation in modified wood, that is, moisture exclusion via the reduction of cell wall voids. Other proposed mechanisms, such as enzyme nonrecognition, micropore blocking, and reducing the number of free hydroxyl groups, may reduce the degradation rate when cell wall water uptake is no longer impeded.

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Growth behavior of wood-destroying fungi in chemically modified wood: wood degradation and translocation of nitrogen compounds

Holzforschung ◽

10.1515/hf-2020-0252 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Lukas Emmerich ◽

Maja Bleckmann ◽

Sarah Strohbusch ◽

Christian Brischke ◽

Susanne Bollmus ◽

...

Keyword(s):

Protective Action ◽

Treated Wood ◽

Untreated Wood ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

Decay Fungi ◽

Chemically Modified ◽

Decay Tests ◽

Modified Wood

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.

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Resistance of thermally modified and pressurized hot water extracted Scots pine sapwood against decay by the brown-rot fungus Rhodonia placenta

European Journal of Wood and Wood Products ◽

10.1007/s00107-019-01482-z ◽

2019 ◽

Vol 78 (1) ◽

pp. 161-171 ◽

Cited By ~ 5

Author(s):

Michael Altgen ◽

Suvi Kyyrö ◽

Olli Paajanen ◽

Lauri Rautkari

Keyword(s):

Cell Wall ◽

Mass Loss ◽

Scots Pine ◽

Elevated Temperatures ◽

Brown Rot ◽

Decay Resistance ◽

Hot Water ◽

Decay Fungi ◽

Effective Reduction ◽

Cell Wall Porosity

AbstractThe thermal degradation of wood is affected by a number of process parameters, which may also cause variations in the resistance against decay fungi. This study compares changes in the chemical composition, water-related properties and decay resistance of Scots pine sapwood that was either thermally modified (TM) in dry state at elevated temperatures (≥ 185 °C) or treated in pressurized hot water at mild temperatures (≤ 170 °C). The thermal decomposition of easily degradable hemicelluloses reduced the mass loss caused by Rhodonia placenta, and it was suggested that the cumulative mass loss is a better indicator of an actual decay inhibition. Pressurized hot water extraction (HWE) did not improve the decay resistance to the same extent as TM, which was assigned to differences in the wood-water interactions. Cross-linking reactions during TM caused a swelling restraint and an effective reduction in moisture content. This decreased the water-swollen cell wall porosity, which presumably hindered the transport of degradation agents through the cell wall and/or reduced the accessibility of wood constituents for degradation agents. This effect was absent in hot water-extracted wood and strong decay occurred even when most hemicelluloses were already removed during HWE.

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Fungal decay resistance of wood reacted with phosphorus pentoxide-amine system

Holzforschung ◽

10.1515/hf.2004.048 ◽

2004 ◽

Vol 58 (3) ◽

pp. 311-315 ◽

Cited By ~ 4

Author(s):

H.-L. Lee ◽

G.C. Chen ◽

R.M. Rowell

Keyword(s):

Brown Rot ◽

Decay Resistance ◽

Phosphorus Pentoxide ◽

White Rot ◽

White Rot Fungus ◽

Gloeophyllum Trabeum ◽

Brown Rot Fungus ◽

Nitro Derivatives ◽

Amine System

Abstract Resistance of wood reacted in situ with phosphorus pentoxide-amine to the brown-rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolor was examined. Wood reacted with either octyl, tribromo, or nitro derivatives were more resistant to both fungi. Threshold retention values of phosphoramide-reacted wood to white-rot fungus T. versicolor ranged from 2.9 to 13.3 mmol, while these for brown-rot fungus G. trabeum ranged from 8.1 to 19.2 mmol. Wood reacted with phosphoramide tested to be more resistant to white-rot than brown-rot attack.

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Leachability and Decay Resistance of Wood Polyesterified with Sorbitol and Citric Acid

Forests ◽

10.3390/f11060650 ◽

2020 ◽

Vol 11 (6) ◽

pp. 650 ◽

Cited By ~ 2

Author(s):

Greeley Beck

Keyword(s):

Cell Wall ◽

Citric Acid ◽

Moisture Content ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

Modification System ◽

Sorption Behaviour ◽

Wood Modification ◽

Water Saturated

Research Highlights: Polyesterification of wood with sorbitol and citric acid (SCA) increases decay resistance against brown-rot and white-rot fungi without reducing cell wall moisture content but the SCA polymer is susceptible to hydrolysis. Background and Objectives: SCA polyesterification is a low-cost, bio-based chemical wood modification system with potential for commercialisation. Materials and Methods: This study investigates moisture-related properties and decay resistance in SCA-modified wood. Scots pine sapwood was polyesterified at 140 °C with various SCA solution concentrations ranging from 14–56% w/w. Dimensional stability was assessed and leachates were analysed with high-performance liquid chromatography (HPLC). Chemical changes were characterized with attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and spectra were quantitatively compared with peak ratios. Low-field nuclear magnetic resonance (LFNMR) relaxometry was used to assess water saturated samples and decay resistance was determined with a modified EN113 test. Results: Anti-swelling efficiency (ASE) ranged from 23–43% and decreased at higher weight percentage gains (WPG). Reduced ASE at higher WPG resulted from increased water saturated volumes for higher treatment levels. HPLC analysis of leachates showed detectable citric acid levels even after an EN84 leaching procedure. ATR-FTIR analysis indicated increased ester content in the SCA-modified samples and decreased hydroxyl content compared to controls. Cell wall water assessed by non-freezing moisture content determined with LFNMR was found to increase because of the modification. SCA-modified samples resisted brown-rot and white-rot decay, with a potential decay threshold of 50% WPG. Sterile reference samples incubated without fungi revealed substantial mass loss due to leaching of the samples in a high humidity environment. The susceptibility of the SCA polymer to hydrolysis was confirmed by analysing the sorption behaviour of the pure polymer in a dynamic vapour sorption apparatus. Conclusions: SCA wood modification is an effective means for imparting decay resistance but, using the curing parameters in the current study, prolonged low-level leaching due to hydrolysis of the SCA polymer remains a problem.

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Combined effect of boron compounds and heat treatments on wood properties: Boron release and decay and termite resistance

Holzforschung ◽

10.1515/hf.2006.072 ◽

2006 ◽

Vol 60 (4) ◽

pp. 455-458 ◽

Cited By ~ 12

Author(s):

S. Nami Kartal

Keyword(s):

Brown Rot ◽

Wood Properties ◽

Decay Resistance ◽

Heat Treatments ◽

Coptotermes Formosanus ◽

White Rot ◽

White Rot Fungus ◽

Termite Resistance ◽

Brown Rot Fungus ◽

Decay Tests

Abstract The decay and termite resistance of boric acid (BA)- and di-sodium octoborate tetrahydrate (DOT)-treated sugi sapwood was tested in the context of additional heat treatments at two temperature levels. Heat treatments had no effect on boron release and almost all boron was leached from specimens during a 10-day weathering period. Decay tests with the brown-rot fungus Fomitopsis palustris and the white-rot fungus Trametes versicolor and a 3-week termite resistance test with the subterranean termite Coptotermes formosanus were performed. Heat treatments did not increase the decay resistance of either BA- or DOT-treated specimens against the brown-rot fungus. However, the decay resistance of BA-treated specimens against the same fungus increased after heat treatment at 220°C for 2 h. Heat treatments at 180°C for 4 h and 220°C for 2 h also resulted in increased decay resistance of DOT-treated specimens against T. versi-color. Increased resistance against termite attack was observed only in DOT-treated specimens heated at 180°C for 4 h or at 220°C for 2 h. Accordingly, a synergistic effect between heat and DOT treatments was observed for resistance against white-rot decay and termites.

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Synthesis of ethylene maleic anhydride copolymer containing fungicides and evaluation of their effect for wood decay resistance

Holzforschung ◽

10.1515/hf.2008.062 ◽

2008 ◽

Vol 62 (4) ◽

Author(s):

George C. Chen

Keyword(s):

Maleic Anhydride ◽

Active Agent ◽

Wood Decay ◽

Decay Resistance ◽

White Rot ◽

White Rot Fungus ◽

Dimethyl Formamide ◽

Poly Ethylene ◽

Maleic Anhydride Copolymer ◽

Hydroxy Quinoline

Abstract The aim of the present study was to combat wood decay based on the approach controlled-release biocides from polymers. The possibility of introducing polymer-bonded fungicides into the cell lumens was investigated. The synthesis of ethylene maleic anhydride copolymer containing pentachlorophenol (penta) and 8-hydroxy quinoline (8HQ) in N, N dimethyl formamide is described. It was demonstrated that the penta-bonded acrylate is a poly(ethylene co-dipentachlorophenyl diacrylate), which has a disubstituted pentachlorophenyl group linked through two acrylate ester bonds. The reaction of ethylene maleic anhydride copolymer with 8-hydroxy quinoline leads to products containing 44.8% poly(ethylene co-8-hydroxy quinolinyl acrylate) and 55.2% of unreacted poly(ethylene co-maleic anhydride). Wood impregnated with the polymers described prevented decay by a brown- and white-rot fungus, even after water leaching. Wood treated with the fungicide pentachlorophenol (penta) alone prevented only decay by a brown-rot fungus. An advantage is that high loading of penta in polymer can be achieved. Moreover, there is a slow-release effect on the active agent due to hydrolysis of ester bonds. The decay resistance of wood treated with poly(ethylene co-8-quinolinyl acrylate) was similar to that of wood impregnated with 8-hydroxy quinoline.

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Treatment of wood with aminofunctional silanes for protection against wood destroying fungi

Holzforschung ◽

10.1515/hf.2006.035 ◽

2006 ◽

Vol 60 (2) ◽

pp. 210-216 ◽

Cited By ~ 40

Author(s):

Steffen Donath ◽

Holger Militz ◽

Carsten Mai

Keyword(s):

Quaternary Ammonium ◽

Prolonged Exposure ◽

Sol Gel ◽

Combined Treatment ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

White Rot Fungus ◽

Ammonium Compound ◽

Amino Groups

AbstractDifferent aminofunctional silanes were tested for their suitability to preserve wood against basidiomycetes in a mini-block experiment according to EN 113. High effectiveness against the brown rot fungusConiophora puteanawas maintained over prolonged exposure times of up to 18 weeks. Resistance against the white rot fungusTrametes versicolorwas only enhanced in the initial phase of exposure (6 weeks); after longer exposure times of 18 weeks, considerable mass losses were observed. It was shown that the antifungal resistance was caused by the amino groups of the oligomeric silane systems, while alkyl groups, which influence the water uptake of wood, only had a minor impact. For effective protection, acidic conditions of the treatment solution were important; this promotes the formation of cationised amino groups (ammonium). The silane quaternary ammonium compound (Si-QAC) 3-(trimethoxysilyl)propyldimethyloctadecyl ammonium chloride was applied in combination with an oligomeric silane system to incorporate quaternary ammonium sites into a SiO2matrix via a sol-gel process. This combined treatment significantly enhanced the decay resistance of pine wood againstC. puteana.

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Durability Improvement of Bio-Based Material by Polymer

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.495 ◽

2011 ◽

Vol 675-677 ◽

pp. 495-498

Author(s):

Yong Feng Li ◽

Yi Xing Liu ◽

Yun Lin Fu ◽

Qing Lin Wu ◽

Xiang Ming Wang

Keyword(s):

Service Life ◽

Maleic Anhydride ◽

Porous Structure ◽

Strong Interaction ◽

Treated Wood ◽

Decay Resistance ◽

Hydroxyl Group ◽

Hydroxyl Groups ◽

Ftir Analysis

Bio-based materials such as wood, bamboo, bio-straw material are vulnerable to degradation by microorganisms and susceptible to change in dimension under humidity, which greatly reduced their service life. In this study, a novel thought was inspired from the unique porous structure of bio-based material that durability of wood may be capable of being improved by generating polymer in situ the special structure. Maleic anhydride (Man) and Styrene (St) were used to penetrate into wood for further copolymerization. SEM observation shows that polymer filled in wood porous structure and tightly contacted wood matrix (i.e. biopolymers), indicating strong interaction between them. FTIR analysis indicates that polymer chemically grafted onto wood matrix by reaction of anhydride group and hydroxyl group. As the amount of hydroxyl groups greatly reduced for their reacting with polymer, the dimensional stability of wood immersing in water was improved; and as the reaction of wood with polymer, the biopolymers were wrapped by resultant polymer, preventing the sample from attack of microorganisms, thus decay resistance of treated wood against microorganisms was greatly improved. Both of them contributed to the improvement of wood durability.

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Durability and Fire Performance of Charred Wood Siding (Shou Sugi Ban)

Forests ◽

10.3390/f12091262 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1262

Author(s):

Laura Hasburgh ◽

Samuel Zelinka ◽

Amy Bishell ◽

Grant Kirker

Keyword(s):

Oxygen Consumption ◽

Cone Calorimeter ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

White Rot Fungus ◽

Fire Performance ◽

Soil Block ◽

Brown Rot Fungus ◽

Charred Wood

Shou sugi ban, also known as yakisugi, or just sugi ban, is an aesthetic wood surface treatment that involves charring the surface of dimensional lumber, such as exterior cladding. The goal of this research is to examine the effect of shou sugi ban on the flammability and decay resistance of wood. Several species and variants of commercially available sugi ban were tested. The flammability was examined from the heat release rate curves using the oxygen consumption method and cone calorimeter. Durability was examined with a soil block assay for one white-rot fungus and one brown-rot fungus. The testing showed that the shou sugi ban process did not systematically improve the flammability or durability of the siding

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