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Wood treatment with organosilanes – perspective for IPBC stabilization
2014 - IRG/WP 14-30641
The aim of the research was a new model preservative’s antifungal properties evaluation. The formulation contained 3-Iodo-2-propynyl butylcarbamate (IPBC) at the reduced concentration. The IPBC was combined with organosilicon compounds (i.e. alkilosilicones with amino groups or fluorine) for supporting its antifungal properties. Due to the fact, that IPBC can be easily destabilized under the influence of iron oxide or higher temperature, the model formulation contained pigments and as a ready to use (RTU) formulation was subjected to appropriate ageing procedure. The chemical analysis was performed to determine the IPBC concentration in RTU formulation and in the treated wood. The biological examination was performed against microfungi (A. niger, T. viride, P. variotii) and wood destroying fungi (C. puteana).
W Perdoch, B Mazela, A Waśkiewicz

A practical method to evaluate the dimensional stability of wood and wood products
1990 - IRG/WP 2342
This paper presents a new simple method to evaluate wood and wood products for their resistance to swelling and to assess wood preservatives for their ability to dimensionally stabilize treated wood exposed to water. Permeable wood of various dimensions and treated with different preserving chemicals have been measured for swelling in the radial and tangential direction during immersion in liquid water. The results indicate that a simple exponential function describing the dimension of the samples during immersion can be used to evaluate both the water-repellency and anti-swelling effectiveness of wood preserving chemicals. The results can be achieved in reasonable time, and the parameters of the function can be determined by a commercial desk-top computer program.
J P Hösli

Tebuconazole, a new wood-preserving fungicide
1990 - IRG/WP 3634
TEBUCONAZOLE, an anti-fungal triazole compound, has been tested to assess the effectivness as wood preserving fungicide. Tests were made with the active ingredient and also in formulations against basidiomycetes, blue-staining fungi and mould. Results of the DESOWAG laboratories and also from official institutes will be presented. In addition to this there were made different toxicological and ecotoxicological trials according to OECD and EPA guidelines
B Wüstenhöfer, H-W Wegen, W Metzner

Discussion of diiodomethyl p-tolyl sulfone (Amical® 48) as a fungicide for wood preservatio
1987 - IRG/WP 3425
The effectiveness of diiodomethyl-p-tolyl sulfone (Amical® 48) as a fungicide for preservation of wood is supported by a discussion of results from the literature and current research programs.
J M Stamm, K J Littel, F M H Casati, M B Friedman

Synergistic effects between 2-HPNO, Irganox 1076 and EDTA on the inhibition of wood degradation by Coriolus versicolor
2004 - IRG/WP 04-30331
The efficiency of 2-hydroxypyridine-N-oxide (2-HPNO) as wood preservative has been investigated. As shown using classical experiments as well as using response surface methodology, the efficiency of 2-HPNO as wood preservative is strongly improved in presence a chelator like EDTA and/or of Irganox 1076 an industrial antioxidant. In these conditions, wood preservative efficiency of the mixture the three previous compounds is quite similar to that of tebuconazole used alone. 2-HPNO exhibits an hydroxamic acid function and is a susbtrate of fungal peroxidase. These properties could explain the observed synergy. The implications of these data for the design of new wood preservation strategies are also discussed.
A Mabicka, S Dumarçay, N Rouhier, M Linder, J P Jacquot, P Gérardin, E Gelhaye

Long-term performance of a "wax" type additive for use with water-borne pressure preservative treatments
2000 - IRG/WP 00-40159
Field performance results are updated for matched CCA treated decking boards with and without an emulsion water repellent additive incorporated with the initial pressure treatment. Decks have been exposured for over 9 years in Harrisburg, NC. Boards were evaluated for in-service and laboratory performance for water repellent efficacy, as well as additive loadings in the boards after this exposure. All results support that these additives can provide long-term protection against many of the physical defects that develop in pressure treated wood during exposure.
A R Zahora

Dimensional stabilization of wood with dimethylol compounds
1987 - IRG/WP 3412
This study showed that a substantial degree of dimensional stability can be imparted to wood by crosslinking with low concentrations of dimethyloldihydroxyethyleneurea. It was demonstrated that by selecting the right catalyst system the cure temperature can be reduced to the point that strength loss of the treated wood is minimized.
D D Nicholas, A D Williams

Evaluation of an alkyl ammonium compound as a fungicide to control sapstain and mould during diffusion storage
1984 - IRG/WP 3282
An alkyl ammonium compound ('Akzo' ES 255) was evaluated for its effectiveness against mould and sapstain during diffusion storage of boron-treated rubber wood. Though ES 255 at 1.0% concentration was effective against mould (71%) and sapstain (89%) it is less satisfactory compared to 0.5% sodium pentachlorophenoxide against mould (92%) and sapstain (98%).
R Gnanaharan

Tolylfluanid - fungicide against blue stain in service
1992 - IRG/WP 92-3736
Physical and chemical properties and efficacy of Tolylfluanid are compared with the properties of Dichlofluanid. Whereas the difference in the molecular structure influences the physical properties significantly, the efficacy of both fungicides is comparable. The toxicological and ecotoxicological profile of Tolylfluanid is summarised.
H-U Buschhaus

Tebuconazole - a new triazole fungicide for wood preservation
1991 - IRG/WP 3680
The great potential of Tebuconazole for wood preservation is demonstrated. Test carried out by official institutes shown that Tebuconazole is particularly effective against wood-rotting basidiomycetes strains. The efficacy of Tebuconazole against the brown rot Gloeophyllum trabeum is outstanding: the toxic value measured in accordane with EN 113, without·ageing, after leaching (EN 84) and after evaporative ageing (EN 73) are below 0.051 kg/m³.
O Exner

Mold inhibition on unseasoned southern pine
2003 - IRG/WP 03-10465
Concerns about indoor air quality due to mold growth have increased dramatically in the United States. In the absence of moisture management, fungicides need to be developed for indoor use to control mold establishment. An ideal fungicide for prevention of indoor mold growth on wood-based materials needs to specifically prevent spore germination and provide long-term protection under conditions of high humidity. Fungicides intended for indoor use must exhibit no mammalian toxicity, be odorless and emit no VOCs. Classes of compounds meeting one or more of these criteria include acids, phenolic compounds (antioxidants), pharmaceuticals, commercial and experimental wood preservatives, food preservatives, and plant essential oils. Wood preservatives and food preservatives were initially screened at various concentrations for inhibitory properties to mold fungi on 2% malt agar (MA). Many compounds that inhibited the test fungi on MA failed to substantially inhibit mold growth on unseasoned southern pine at higher concentrations than the minimal inhibitory concentration determined on MA. Subsequently, compounds were screened on unseasoned southern pine stakes. Pine stakes were dipped for 15 seconds in varying concentrations of the test chemicals according to the ASTM standard test method D4445 for controlling mold on unseasoned lumber. Stakes were challenged with Penicillium chrysogenum PH02, Aspergillus niger 2.242, and Trichoderma viride ATCC 20476 spore preparations. Following a 4-wk incubation, stakes were rated from 0-5 with 5 representing heavy mold growth. An inihibition rating of 0 to 1 is indicative of successful mold inhibition. The best overall average ratings for wood preservatives were seen in stakes treated with 5% Bor-A-plus or Cu+, which were highly inhibitory to all test fungi. High concentrations of ethanolamine (10%) and thujaplicin (10%) were inhibitory to all test fungi. Pine resin (50%) solely inhibited P. chrysogenum. Of the food preservatives tested, five percent sodium benzoate and potassium sorbate inhibited all test fungi, while calcium propionate selectively inhibited A. niger. Pharmaceutical antifungals such as voriconazole (2.5mg/mL), thiabendazole (25mg/mL), and miconazole (20mg/mL) completely inhibited all test fungi on unseasoned pine, while other azole-derivatives failed to inhibit mold growth. Nystatin (10,000 units/mL) inhibited only A. niger. A combination of effective chemicals should be considered as one strategy to provide long-term protection of wood-based building materials from mold establishment.
C A Clausen, V W Yang

Combined effects of the treatment of wood with formaldehyde
1978 - IRG/WP 3117
Treatment of fibrous materials with reagents in a vapor phase is neither new nor unique. Numerous examples exist in literature of vapor phase experiments on cellulose fibers and fabrics, and on wood. For many years the textile research and industry have used vapor phase processes for the treatment of textiles. The chemical modification of cellulose is based on different types of reactions e.g. esterification, alkylation, resin formation or polymerization, monomer grafting and crosslinking. Vapor phase treatment of wood offers certain potential advantages over the conventional liquid phase wood impregnation. The higher mobility of low molecular weight compounds in the gaseous state ensures a rapid, uniform and homogeneous distribution throughout the wood structure. The vapor phase treatment of wood is also a better approach from the standpoint of cell wall penetration. Bulking, which takes place in the cell wall only, means that less chemicals are required and that the final weight of the composite is limited. Furthermore, due to the low viscosity of a gas, the application of a lower pressure differential remains possible. Within the framework of a wood improvement programme carried out at the Laboratory of Wood Biology and Wood Technology (University of Ghent, Belgium) the treatments were based on the impregnation of wood with liquid synthetic monomers and with gaseous formaldehyde. The results of the hygroscopic and dimensional behaviour of the wood-plastic-combinations have been published previously. Other papers deal with the physical and chemical interactions between the synthetic products and the natural polymers of the cell wall. This contribution will be restricted to the treatment of wood with formaldehyde in the gaseous state.
M Stevens, J Schalck

The use of TCMTB in applications other than sapstain prevention: A review
1990 - IRG/WP 3606
The efficacy of TCMTB against staining fungi and surface moulds has been thoroughly investigated during the last decade. As a result, the chemical is used as an alternative to the chlorinated phenols in various parts of the world for the preservation of freshly sawn timber. Less known are the data obtained against brown rot, white rot and soft rot fungi. The termite repellent and bactericidal properties of the chemical widen the scope of application possibilities. The objective of this article is to report on the data actually available.
R Van der Eynde

Resistance of painted wood to mould fungi. Part 2. The effect of wood substrate and acrylate paint systems on mould growth
1997 - IRG/WP 97-10234
Resistance of acrylate paint systems on different types of pine and spruce sapwood to mould fungi was studied. Dipping into the preservative prior to painting, a primer with and without a fungicide (propiconazole + IPBC 0.50 + 0.2%) and a topcoat with and without a fungicide (propiconazole + IPBC 0.25 + 0.12%) were combinations of the treatments studied. The efficacy of the treatment systems varied, but the wood material also affected the ability of the paint systems to resist mould growth on the paint surface. The kiln-dried yellow surfaces of the pine and spruce sapwood were more susceptible to mould growth than the spruce surface sawn 10 mm below the original kiln-dried surface. On the resawn spruce material, the most effective treatments were free from mould growth after 26 weeks at RH 100%. However, the effect was markedly lower on the kiln-dried surfaces of pine and spruce sapwood. The influence of natural weathering on the mould growth will be a next stage of the study. The study is a part of a project CT94-2463 in the AIR programme of DG XII.
H Viitanen, P Ahola

Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in the strength of the wood. The effect of the specific properties of catalysts on the cross-linking and hydrolytic reactions as well as the reaction kinetics have been inadequately investigated. Investigations on the treatment of wood with formaldehyde were started in 1976 at the Forest Products Laboratory of the Technical Research Centre of Finland. In the beginning, HCl-catalysed treatments were used which proved to reduce the strength properties of wood rather strongly. In continued trials more satisfactory catalysts have been sought in order to achieve maximal formaldehyde cross-linking and minimal degradation of the wood. The tests have included various inorganic and organic acids and metal halides soluble in water as well as sulphur dioxide (SO2) and boron trifluoride (BF3) in vapour phase. Some of the results are reviewed in this paper.
T Vihavainen, K Piispanen, P Mansikkamäki

Evaluating possibilities of leaching of deltamethrin and TCMTB (insecticides and fungicide for protecting wood) by rain water or by soaking in water
1988 - IRG/WP 3464
Deltamethrin and TCMTB have been subjected to several field leaching tests on freshly fallen trees and in the laboratory, using standard EN 84. All the trials gave the same results and confirm that Deltamethrin and TCMTB are not washed out after they have been allowed to penetrate the trunk surface properly. According to the EN 84 standard, less than 1% Deltamethrin and less than 1.7% TCMTB were released in water after a 14 day leaching period
J S Duguet, V Dartigues

Improvements of stability and durability of beechwood (Fagus sylvatica) by means of treatment with acetic anhydride
1991 - IRG/WP 3645
In the present investigations, beechwood (Fagus sylvatica) was treated with non-catalysed acetic anhydrid at 120°C and some physical- and biological parameters of the treated wood were compared with those of non-treated wood. The radial and tangential shrinkage and swelling, respectively, and the absorption capacity of the acetylated wood against moisture is considerably lower. The durability against fungi improves. The results are discussed.
H Militz

Adsorption of ACQ and CuMEA Wood Preservatives in Red pine
2005 - IRG/WP 05-30374
The rates of stabilization or fixation of ACQ subcomponents (CuO, DDAC and MEA) in red pine (Pinus resinosa) were compared for different solution concentrations (0.75%, 1.5%, 2.25% and 3% ACQ-D) and post treatment conditioning temperatures. Preservative solutions were impregnated into red pine sapwood by a full-cell treatment. Copper and MEA adsorptions from copper monoethanolamine solutions without DDAC were also evaluated for comparison. After the treatments, samples were conditioned without drying either at 22° C for seven weeks or at 50° C for one week. At different times after treatment, expressate from the specimen blocks was analyzed for copper, DDAC and MEA. Copper and MEA adsorption by the wood cell walls followed similar trends. The equilibrium copper adsorption ranged from 44% at high ACQ retentions to about 95% for the lowest retention while the values in the CuMEA system were slightly higher for the higher retentions, ranging from about 54% to 93%. This suggests that DDAC may compete with CuMEA for reaction sites at high ACQ concentrations. Adsorption of DDAC into the wood cell wall matrix was rapid; at all solution concentrations, more than 80% of DDAC was adsorbed by red pine sapwood within minutes after treatment.
C Tascioglu, P A Cooper, Y T Ung

The effects of chemical modification on the physical properties of alder and spruce particleboards
2005 - IRG/WP 05-40300
In this paper, it was aimed to improve some physical properties of chemically modified particleboard, made from spruce and alder species, spreading widely at Black sea region in Turkey. Spruce and alder chips were reacted with acetic, succinic, maleic and phthalic anhydrides at constantly heat for 3 hours then, hot pressed at 150 °C by using Phenol formaldehyde (PF) resin. Target board density was 650 kg/m3. Density, moisture content, thickness swelling and water absorption rate were determined on the chemically modified boards, reacted with four different anhydrides. Results were compared with control boards. Chemical modification of boards reacted with anhydrides resulted in improved thickness swelling and water absorption values. The best results were determined boards reacted with acetic and succinic anhydride treatments than the others.
E Dizman, Ü C Yildiz, H Kalaycioglu, S Yildiz, A Temiz, E D Gezer

Integrated protection of freshly sawn lumber using Bacillus subtilis and selected fungicide
1997 - IRG/WP 97-10235
Bioprotection against stain fungi has tremendous potential for reducing discoloration of freshly sawn wood while decreasing chemical consumption. Unfortunately, most bioprotectants appear to be unable to consistently perform under the array of conditions to which freshly sawn wood is exposed. While research is underway to understand the nature of the inconsistent performance, a more pragmatic approach to solving this problem is to alter the environment to more consistently favor the bioprotectant. One method for accomplishing this task is to apply low levels of biocides at the same time as the bioprotectant is applied. The biocide, although used below the threshold tor preventing fungal growth, should render the stain fungi less fit and, therefore, more susceptible to control. In this report, we evaluated the effect of 3 commonly used fungicide mixtures on the ability of B. subtilis to inhibit discoloration by a mixture of Ophiostoma perfectum, Phialphora spp., and Alternaria alternata on Pinus ponderosa sapwood under laboratory conditions. Bacillus subtilis provided poor control of discoloration. The addition of fungicide produced no enhancement of bioprotection. Evaluation of bacterial cultures containing this fungicide indicated that the chemicals had a profound effect on bacterial filters.
M E Mankowski, M Anderson, J J Morrell

Properties-enhanced albizzia particleboards by incorporating fungicide and insecticide in the glue
1994 - IRG/WP 94-30060
Preservative-treated particleboards were prepared by using tropical fast-growing albizzia and adding fungicides and insecticides to the adhesive-glue. the physical and biological properties of these boards were evaluated. No significant reduction in bending or internal-bond strength due to incorporation of the chemicals was detected. Treated particleboards effectively resisted attack by Coptotermes formosanus at an active ingredient (a.i.) retention of less than 0.5 kg/m³ for chlorpyrifos, dichlorophenthion and propetanphos in laboratory tests. Although decay was unaffected by incorporating the mixed preservative at the retention levels in this study, boards which contained IF-1000 as a fungicide an an a.i. retention of more than 1.0 kg/m³ showed the possibility of decay resistance.
B Subiyanto, S Yusuf, Y Imamura, S Fushiki, T Saito, T Katuzawa

Comparative field performance of CCA and CCA-water repellent treated Southern pine lumber
1995 - IRG/WP 95-30089
This paper describes the field performance of end-matched southern pine boards treated with either CCA type C or CCA type C containing an emulsion water repellent (WR) additive. Boards were either kiln or air-dried after treatment, constructed into decks, and exposed for over 3 years at Harrisburg, NC. During this exposure, matched boards were monitored for internal moisture content, cupping at midpoint, checking, and degree of nail pull. The CCA-only treated boards display rapid changes in moisture content, check width, and degree of cupping that was directly influenced by rainfall. Although boards treated with CCA and the water repellent additive are starting to lose the characteristic of surface water beading, the boards continue to show greatly improved in-service dimensional stability compared with matched CCA-only treated boards. The effectiveness of the water repellent additive in reducing physical degrade during service exposure is manifested in greatly reduced check development and nail pull when compared to the CCA-only treated boards.
A R Zahora

Tebuconazole - A new triazole fungicide for wood preservation
1990 - IRG/WP 3629
The main cause of economic damage to timber and millwork worldwide are Basidiomycetes (brown and white rot). After testing a wide range of triazole derivatives for their effectiveness against decay fungi, Tebuconazole, a triazole compound, was selected. The physico-chemical, toxicological and ecotoxicological data of this substance are described. Tebuconazole is unleachable, light-stable, heat-stable and suitable for use in both solvent-borne and water-borne formulations. Tests carried out by official institutes show that Tebuconazole is resistant to both leaching and evaporation. Toxic values measured in accordance with EN 113 and EN 73 (e.g. Gloeophyllum trabeum: 0.03-0.08 kg/m³ a.i.) reveals the great potential of Tebuconazole to protect treated wood against decay fungi.
R Gründlinger, O Exner

Dimensional stabilization and decay resistance of wood treated with brown-rotted lignin and copper sulfate
1990 - IRG/WP 3608
The objective of this study was to evaluate the potential usefulness of brown-rotted lignin (BRL) as a dimensional stabilization and copper complexing agent for wood treatment. For dimensional stabilization, aqueous solutions of the lignin extract were combined with either copper sulfate, glyoxal or other additives. Anti-shrink efficiency (ASE) values as high as 42% were obtained with wood treated with a BRL/Cu combination. By treating wood with a 6% solution of the lignin extract prior to treatment with copper sulfate, a two-fold increase in fixation of copper was attained. Soil block tests were also performed on wood treated with BRL and copper sulfate individually as well as in combination; it was found that the BRL increased the activity of Cu against Poria placenta.
L Jin, D D Nicholas, T Schultz

The suitability of isothiazolone microemulsions as long term wood preservatives
1997 - IRG/WP 97-30150
Microemulsion formulations of 4,5 dichloro-2-n-octyl-4-isothiazolin-3-one were investigated to determine the leaching potential of these formulation types as well as their efficacy against decay fungi. These patented low leaching formulations exhibited good anti fungal efficacy in standard tests combined with minimal leaching of the active ingredient from the wood. The data suggests that the excellent long term efficacy ( > 10 yrs) recorded in field tests on solvent borne formulations can be repeated with these emulsion formulations. Active ingredient analysis show an excellent penetration and macrodistribution throughout the samples. Preliminary studies using various instrumental analytical techniques on active ingredient microdistribution at the cellular level show an even distribution throughout the cell wall layers. The data indicates that these microemulsion formulations are an excellent vehicle / carrier for solubilization of a water insoluble biocide, its transport and homogenous distribution into the wood without adversely effecting its permanence or efficacy in the wood during long term service.
B M Hegarty, Bing Yu, L E Leightley

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