The Resistance of Wood Chemically Modified with Isocyanates. Part 1. Brown Rot, White Rot and Acid Chlorite Delignification

Holzforschung ◽  
1999 ◽  
Vol 53 (3) ◽  
pp. 230-236 ◽  
Author(s):  
F. Cardias Williams ◽  
M.D. Hale
Keyword(s):  
Chemical Modification ◽  
Weight Percent Gain ◽  
Brown Rot ◽  
Weight Percent ◽  
Pinus Nigra ◽  
Fungal Species ◽  
White Rot ◽  
Sodium Chlorite ◽  
Pycnoporus Sanguineus ◽  
Wood Protection

Summary This study was to assess the bioprotectant performance of chemical modification with three different isocyanates (n-butyl, hexyl and 1,6-diisocyanatohexane, BuNCO, HeNCO and HDI respectively) in Corsican pine (Pinus nigra Schneid) sapwood. Wood-isocyanate bond formation was verified by the increase in sample weight, volume and by infra-red spectroscopy. Basidiomycete (Coniophora puteana, Gloeophyllum trabeum, Coriolus versicolor, Pycnoporus sanguineus) decay tests demonstrated protection by chemical modification. The relationships of fungal species, weight percent gain (WPG), and decay induced weight loss were examined. One of the brown rot fungi, C. puteana, showed higher threshold protection values than the other fungi tested and the diisocyanate showed better performance. Chemical characteristics of the sound and brown rotted wood (C. puteana) have been examined using sulphuric acid and sodium chlorite procedures to clarify the principles which govern isocyanate modifications and restrict fungal decay. These demonstrated that appreciable wood protection against C. puteana only occurred when the holocellulose fraction showed substantial changes due to chemical modification.

Decay resistance of softwoods and hardwoods thermally modified by the Thermovouto type thermo-vacuum process to brown rot and white rot fungi

Holzforschung ◽  
2016 ◽  
Vol 70 (9) ◽  
pp. 877-884 ◽  
Author(s):  
Jie Gao ◽  
Jong Sik Kim ◽  
Nasko Terziev ◽  
Geoffrey Daniel
Keyword(s):  
White Rot Fungi ◽  
Brown Rot ◽  
Decay Resistance ◽  
Fungal Species ◽  
White Rot ◽  
Agar Block ◽  
Pycnoporus Sanguineus ◽  
Postia Placenta ◽  
Soil Block ◽  
Class 1

Abstract Softwoods (SW, spruce and fir) and hardwoods (HW, ash and beech) were thermally modified by the thermo-vacuum (Termovuoto) process for 3–4 h in the temperature range 160–220°C (TMW160–220°C) and their fungal durability were examined in soil-block tests with two brown rot (BR, Postia placenta, Gloeophyllum trabeum) and two white rot (WR, Pycnoporus sanguineus, Phlebia radiata) fungi. SW-TMW160–220°C were exposed to P. placenta and P. sanguineus and HW-TMW190–220°C to all fungal species. Considerable improvement (durability class 1–3) in decay resistance was only achieved for SW- and HW-TMW220°C. Thermal modification (TM) below 200°C influenced decay resistance negatively in case of some fungal species applied for both SW and HW. Judged by the durability class, decay resistance was higher in HW- than in SW-TMW at high TM temperature. Behavior of TM differed significantly between ash (ring-porous HW) and beech (diffuse-porous HW). A comparison between results of soil- and agar-block tests on Termovouoto wood demonstrated that the influence of testing method in terms of assignment to durability classes is not significant.

scholarly journals Influence of Copper and Biopolymer/Saqez Resin on the Properties of Poplar Wood

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 667 ◽  
Author(s):  
Huijun Dong ◽  
Mohsen Bahmani ◽  
Sohrab Rahimi ◽  
Miha Humar
Keyword(s):  
Physical Properties ◽  
Trametes Versicolor ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Decay Resistance ◽  
White Rot ◽  
White Rot Fungus ◽  
Poplar Wood ◽  
Wood Protection ◽  
Increasing Trend

There is an increasing trend in the use of environmentally-friendly materials in wood protection. This includes the use of less toxic active ingredients, as well as better fixation. This study investigates the formulation based on the combination of copper and Saqez resin on the physical and biological resistance properties of poplar wood. Samples were treated by either copper-ethanolamine (Cu/MEA) and/or Saqez resin at various treatment levels. A vacuum pressure procedure was applied. The retention, weight percent gain, water absorption, volumetric swelling, and decay resistance of the samples were then determined. The highest retention and weight percent gain were obtained in the samples treated with the combination of copper-based system and Saqez resin. Additionally, the combination of the copper and Saqez improved the physical properties and decay-resistance against white-rot fungus Trametes versicolor.

scholarly journals Influence of Copper and Biopolymer/Saqez Resin on the Properties of Poplar Wood

2020 ◽  
Author(s):  
Huijun Dong ◽  
Mohsen Bahmani ◽  
Sohrab Rahimi ◽  
Miha Humar
Keyword(s):  
Physical Properties ◽  
Trametes Versicolor ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Decay Resistance ◽  
White Rot ◽  
White Rot Fungus ◽  
Poplar Wood ◽  
Wood Protection ◽  
Protection Technology

There is an increasing interest in applying environmentally-friendly materials in wood protection technology. This include the use of less toxic active ingredients, as well as better fixation. This study investigates the formulation based on the combination of copper and Saqez resin on the physical and biological resistance properties of poplar wood. Samples were treated by either copper-ethanolamine (Cu/MEA) and/or Saqez resin at various treatment levels. A vacuum pressure procedure was applied. The retention, weight percent gain, water absorption, volumetric swelling, and decay resistance of the samples were then determined. The highest retention and weight percent gain were obtained at the samples treated with the combination of copper-based system and Saqez resin. Additionally, the combination of the copper and Saqez improved the physical properties and decay-resistance against white-rot fungus Trametes versicolor.

The fungal resistance of wood modified with glutaraldehyde

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Zefang Xiao ◽  
Yanjun Xie ◽  
Carsten Mai
Keyword(s):  
Scots Pine ◽  
Beech Wood ◽  
Weight Percent Gain ◽  
Brown Rot ◽  
European Beech ◽  
Soft Rot ◽  
Weight Percent ◽  
Fungal Resistance ◽  
White Rot ◽  
White Rot Fungus

Abstract Scots pine sapwood (Pinus sylvestris L.) and European beech wood (Fagus sylvatica L.) were treated with glutaraldehyde (GA) in aqueous solution in the presence of magnesium chloride as a catalyst to evaluate the durability improvement towards staining and rot fungi. The GA modified specimens were dipped in a spore suspension of the blue stain fungus Aureobasidium pullulans and incubated for 8 weeks. The growth on both pine and beech wood was restrained, when the weight percent gain (WPG) of the specimens was above 7%. Under this condition, GA-modified beech wood did not suffer any mass loss after incubation with the white rot fungus Trametes versicolor. The threshold to prevent decay of beech and pine specimens towards the brown rot fungus Coniophora puteana was at a WPG of only 3%. GA treatment to a WPG over 6% protected the Scots pine stakes from soft rot decay during 32 weeks’ exposure according to ENv 807 (2001).

Decay susceptibility of Amazon wood species from Brazil against white rot and brown rot decay fungi 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Jane Silveira Carneiro ◽  
Luciano Emmert ◽  
Gerson H. Sternadt ◽  
Julio César Mendes ◽  
Getúlio F. Almeida
Keyword(s):  
Wood Species ◽  
Wood Decay ◽  
Brown Rot ◽  
White Rot ◽  
Natural Resistance ◽  
Decay Fungi ◽  
Pycnoporus Sanguineus ◽  
Hymenaea Courbaril ◽  
Weight Losses ◽  
Resistant Species

Abstract A total of 28 tropical Amazon woods – many of them rarely used – from Tapajós National Forest, Pará state, Brazil, were tested for their natural resistance against the decay fungi: Ganoderma applanatum, Trametes versicolor, Pycnoporus sanguineus, Meruliporia incrassata, and Gloeophyllum trabeum. The wood resistance classification was made according to the ASTM D 2017-81 method. High variability on susceptibility to wood decay fungi was found. Their mean weight losses varied from 0.6% to 45.6%. Highly resistant species include: Astronium gracile, Bagassa guianensis, Caryocar villosum, Claricia racemosa, Diplotropis purpurea, Dipteryx odorata, Hymenaea courbaril, Manilkara huberi, Mezilaurus itauba, Sextonia rubra, Tabebuia incana, and Vatairea paraensis. The following wood species are less durable: Brosimum parinarioides, Jacaranda copaia, Laetia procera, Pouteria pachycarpa, Virola caducifolia, and Trattinnickia rhoifolia. Meruliporia incrassata caused extensive weight losses in most of the investigated Amazon wood species.

Chemical reaction of maritime pine sapwood (Pinus pinaster Soland) with alkoxysilane molecules: A study of chemical pathways

Holzforschung ◽  
2004 ◽  
Vol 58 (5) ◽  
pp. 511-518 ◽  
Author(s):  
Gilles Sèbe ◽  
Philippe Tingaut ◽  
Rodrigue Safou-Tchiama ◽  
Michel Pétraud ◽  
Stéphane Grelier ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Modification ◽  
Chemical Reaction ◽  
Cell Walls ◽  
Pinus Pinaster ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Maritime Pine ◽  
Water Leaching

Abstract The chemical modification of maritime pine sapwood (Pinus pinaster) with alkoxysilanes was studied according to three different pathways: carbamoylation with 3-isocyanatopropyltriethoxysilane, etherification with 3-glycidoxypropyltrimethoxysilane and alcoholysis of n-propyltrimethoxysilane. Grafting was confirmed by weight percent gain calculations (WPG), infrared spectroscopy (FTIR) as well as 13C and 29Si NMR CP MAS analysis. Signals of the grafted groups in the different spectra were assigned and the reactivity of the trialkoxysilane moieties towards wood was discussed. Experiments with model wood blocks showed that the reactions investigated occurred within the wood cell walls. Grafted chemicals were found to be relatively stable with regard to water leaching but only slight dimensional stabilisation was noted after treatment.

scholarly journals Effects of Wood Moisture Content and the Level of Acetylation on Brown Rot Decay

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 299 ◽  
Author(s):  
Samuel L. Zelinka ◽  
Grant T. Kirker ◽  
Amy B. Bishell ◽  
Samuel V. Glass
Keyword(s):  
Moisture Content ◽  
Mass Loss ◽  
Linear Trend ◽  
Fungal Growth ◽  
Weight Percent Gain ◽  
Brown Rot ◽  
Weight Percent ◽  
Wood Moisture Content ◽  
Wood Moisture ◽  
Brown Rot Decay

Acetylation is one of the most common types of wood modification and is commercially available throughout the world. Many studies have shown that acetylated wood is decay resistant at high levels of acetylation. Despite its widespread use, the mechanism by which acetylation prevents decay is still not fully understood. It is well known that at a given water activity, acetylation reduces the equilibrium moisture content of the wood cell wall. Furthermore, linear relationships have been found between the acetylation weight percent gain (WPG), wood moisture content, and the amount of mass loss in decay tests. This paper examines the relationships between wood moisture content and fungal growth in wood, with various levels of acetylation, by modifying the soil moisture content of standard soil block tests. The goal of the research is to determine if the reduction in fungal decay of acetylated wood is solely due to the reduction in moisture content or if there are additional antifungal effects of this chemical treatment. While a linear trend was observed between moisture content and mass loss caused by decay, it was not possible to separate out the effect of acetylation from fungal moisture generation. The data show significant deviations from previously proposed models for fungal moisture generation and suggest that these models cannot account for active moisture transport by the fungus. The study helps to advance our understanding of the role of moisture in the brown rot decay of modified wood.

Protection mechanisms of DMDHEU treated wood against white and brown rot fungi

Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Pradeep Verma ◽  
Ulrich Junga ◽  
Holger Militz ◽  
Carsten Mai
Keyword(s):  
Cell Wall ◽  
Treated Wood ◽  
Weight Percent Gain ◽  
Brown Rot ◽  
Weight Percent ◽  
Decay Resistance ◽  
Brown Rot Fungi ◽  
Protection Mechanisms ◽  
Mesh Bags ◽  
Fine Wood

AbstractThe resistance of beech and pine wood blocks treated with 1,3-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) againstTrametes versicolorandConiophora puteanaincreased with increasing weight percent gain (WPG) of DMDHEU. Full protection [mass loss (ML) below 3%] was reached at WPGs of approximately 15% (beech) and 10% (pine). Untreated and DMDHEU treated blocks were infiltrated with nutrients and thiamine prior to fungal incubation and it was observed whether the destruction or removal of nutrients and vitamins during the modification process has an influence on the ML caused by the fungi. This study revealed that no considerable differences were found. Then, the cell wall integrity was partly destroyed by milling and the decay of the fine wood powder filled into steel mesh bags was compared to that of wood mini-blocks. The purpose of this study was to examine whether the effects of surface area, cell wall bulking, and reduction in micro-void diameters play a role in decay resistance. The ML caused by the fungi, however, also decreased with increasing WPG and showed comparable patterns similar to the case of mini-blocks. ML of powder bearing the highest WPG appeared to be caused by losses in DMDHEU during fungal incubation. For brown rotted wood, the infrared absorption ratios at 1030 cm-1and 1505 cm-1revealed decreasing decay of polysaccharides with increasing WPG of treated wood.

scholarly journals Enhanced Lignocellulolytic Enzyme Activities on Hardwood and Softwood during Interspecific Interactions of White- and Brown-Rot Fungi

2021 ◽  
Vol 7 (4) ◽  
pp. 265
Author(s):  
Junko Sugano ◽  
Ndegwa Maina ◽  
Janne Wallenius ◽  
Kristiina Hildén
Keyword(s):  
Enzyme Activities ◽  
Interspecific Interactions ◽  
Wood Decay ◽  
Brown Rot ◽  
Species Interaction ◽  
Fungal Species ◽  
White Rot ◽  
White Rot Fungus ◽  
Wood Decomposition ◽  
Brown Rot Fungi

Wood decomposition is a sophisticated process where various biocatalysts act simultaneously and synergistically on biopolymers to efficiently break down plant cell walls. In nature, this process depends on the activities of the wood-inhabiting fungal communities that co-exist and interact during wood decay. Wood-decaying fungal species have traditionally been classified as white-rot and brown-rot fungi, which differ in their decay mechanism and enzyme repertoire. To mimic the species interaction during wood decomposition, we have cultivated the white-rot fungus, Bjerkandera adusta, and two brown-rot fungi, Gloeophyllum sepiarium and Antrodia sinuosa, in single and co-cultivations on softwood and hardwood. We compared their extracellular hydrolytic carbohydrate-active and oxidative lignin-degrading enzyme activities and production profiles. The interaction of white-rot and brown-rot species showed enhanced (hemi)cellulase activities on birch and spruce-supplemented cultivations. Based on the enzyme activity profiles, the combination of B. adusta and G. sepiarium facilitated birch wood degradation, whereas B. adusta and A. sinuosa is a promising combination for efficient degradation of spruce wood, showing synergy in β-glucosidase (BGL) and α-galactosidase (AGL) activity. Synergistic BGL and AGL activity was also detected on birch during the interaction of brown-rot species. Our findings indicate that fungal interaction on different woody substrates have an impact on both simultaneous and sequential biocatalytic activities.

scholarly journals Oil in Water Nanoemulsions Loaded with Tebuconazole for Populus Wood Protection against White- and Brown-Rot Fungi

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1234
Author(s):  
Alejandro Lucia ◽  
Mónica Murace ◽  
Gastón Sartor ◽  
Gabriel Keil ◽  
Ricardo Cámera ◽  
...  
Keyword(s):  
Beech Wood ◽  
Brown Rot ◽  
Vacuum System ◽  
Diameter Distribution ◽  
Hydrodynamic Diameter ◽  
Promising Alternative ◽  
Pycnoporus Sanguineus ◽  
Brown Rot Fungi ◽  
Wood Protection

Eugenol in water nanoemulsions loaded with tebuconazole appear as a very promising alternative formulations for wood protection against xylophagous fungi that are the main species responsible for different rots in wood structures. The dispersions as prepared and upon dilution (impregnation mixtures) were characterized by the apparent hydrodynamic diameter distribution of the oil droplets loaded with tebuconazole and their long-term stability. The impregnation mixtures were applied on wood of Populus canadensis I-214 clone by using a pressure-vacuum system, and the effectiveness against fungal degradation by Gloeophyllum sepiarium and Pycnoporus sanguineus fungi was determined. The retention of tebuconazole in wood was about 40% of the amount contained in the impregnation mixtures. The results showed that the impregnation process leads to a long-term antifungal protection to the wood, with the mass loss after 16 weeks being reduced more than 10 times in relation to the control (untreated poplar wood) and the reference wood (untreated beech wood).

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