Furfurylated wood

Last updated
Example of furfurylated pine wood with a loading level of 30-35%) Beispiel fur Furfuryliertes Holz mit einem Beladungsgrad von 30-35%25.jpg
Example of furfurylated pine wood with a loading level of 30–35%)

Furfurylated wood is the end product of treating wood with furfuryl alcohol. This chemical process is also called furfurylation. Furfurylation is a commercially used wood modification process [1] to enhance the physical, mechanical and biological properties of wood. In this process -which is based on principles of wood science- the cell walls of the wood swell with furfuryl alcohol, which polymerizes within the cell walls. This treatment reduces the water absorption capacity of the wood, thus minimizing its tendency to deform with changes in moisture. The hardness and rot resistance of the modified wood are also improved compared to natural, untreated wood. The furfuryl alcohol used is obtained through the hydrogenation of furfural [2] from biological agriwaste residues, such as husks and bagasse.

Contents

Process

In the furfurylation process, the walls of woody cells are initially swollen with the furfuryl alcohol based solution. Due to its polarity and size, furfuryl alcohol penetrates the cell wall. The polymerization of furfuryl alcohol in wood is a complex reaction whose processes are not fully understood. It is not clear whether furfuryl alcohol reacts and polymerizes only with itself within the cell or if it also reacts with cell wall components such as cellulose or lignin. [3] The polymerized furfuryl alcohol within the cell makes the wood highly hydrophobic. [4]

History

The furfurylation of wood is a process that first initiated and explored by Alfred J. Stamm in the 1950s in the United States, but widespread adoption in the market has been limited so far. [5] The first industrial production of furfurylated wood in the USA began in the 1960s. [5] In the 1980s, a two-stage process was developed by a research group led by Professor Marc Schneider in Canada. The wood was first treated with a catalyst and then soaked with furfuryl alcohol. However, the high cost of the two-stage impregnation prevented the production of furfurylated wood at market-demanded prices. [6] In 1997, Wood Polymer Technologies ASA in Norway was founded in an attempt to build a pilot plant for a single stage production process. [7] From 2000 onwards, furfurylated wood has been marketed in the US and Europe. In 2004, the production capacity in Porsgrunn, Norway, was 3,000 m3 per year. By 2008, the capacity had increased to 25,000 m3 per year. [8]

Production

To produce furfurylated wood, the following steps are necessary: [9]

  1. Storage and mixing of impregnation solution: Approximately 40% furfuryl alcohol, water, polymerization initiators, catalysts, and surfactants are mixed and then poured into a storage tank.
  2. Impregnation: The wood is soaked in a pressure vessel in a three-stage process. First, a vacuum is applied to remove the remaining air from the wood. In the second step, the wood is soaked with the impregnation solution at pressures around 13 bar. Step three involves a short relaxation phase, during which the vessel is brought to ambient pressure. The entire vacuum vessel can be tilted by 5° to allow excess impregnation solution to drain off the boards. [10]
  3. Drying and polymerization: The soaked wood is dried in vacuum dryers through direct heating with steam. Due to the high boiling point of furfuryl alcohol (170 °C), it is possible to first dry the water from the wood and then carry out polymerization at a second higher temperature stage. The condensate produced during drying is returned to the impregnation solution for further use. [10]
  4. Post-drying: The modified wood is post-dried at moderate temperatures to minimize emissions and set the final moisture content. [9]

For the production of furfurylated timber, mostly Radiata pine (Pinus radiata) wood originating from Oceania is used; other wood species used include Southern Yellow Pine from the US, and maple. [8]

Properties

The properties of the modified wood strongly depend on the amount and concentration of furfuryl alcohol introduced. The introduction amount of furfuryl alcohol can be controlled by the proportion of furfuryl alcohol in an aqueous impregnation solution. Thus, it is possible to adjust the properties of the modified wood.

At a loading level of 30–35%, the hardness, weight, mechanical properties, dimensional stability, and resistance to insects, fungi, and chemicals increase to the extent that the product is classified in durability class 1. [11] Due to the process, the wood darkens significantly, especially at high levels of furfuryl alcohol. Therefore, it is traded and used as a substitute for tropical timber, both in terms of properties and colour. The only drawback of highly modified wood is an increase in wood brittleness.

Even at a low loading level, the mechanical properties of the wood improve, but resistance to pests such as fungi and insects is not guaranteed, and the dark discolouration of the wood is less pronounced. Therefore, lightly modified wood is used indoors, mainly as flooring.

At a loading level of 50%, high resistance to maritime ship borers, such as shipworms ( Teredo navalis ), is achieved. [12]

Furfurylated wood, holding the Scandinavian ecological label Swan , is today traded as an environmentally friendly product since both the wood and furfuryl alcohol are produced from renewable raw materials. [13]

In recent years, attempts to make furfurylated wood as a fire resistant material, have been made. [14] [15]

Market

Currently, there is only one manufacturer of furfurylated wood, named Kebony based in Oslo, Norway. This company produces 22,000 m3 of furfurylated wood. The operation has capacities for at least 25,000 m3. [8] A new production plant has been built in Belgium in 2021, and the total production has been increased.

Related Research Articles

<span class="mw-page-title-main">Cellulose</span> Polymer of glucose and structural component of cell wall of plants and green algae

Cellulose is an organic compound with the formula (C
6H
10O
5)
n, a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fiber is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%.

<span class="mw-page-title-main">Wax</span> Class of organic compounds which are malleable at room temperature

Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in nonpolar organic solvents such as hexane, benzene and chloroform. Natural waxes of different types are produced by plants and animals and occur in petroleum.

<span class="mw-page-title-main">Epoxy</span> Type of material

Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called epoxy. The IUPAC name for an epoxide group is an oxirane.

<span class="mw-page-title-main">Varnish</span> Transparent hard protective finish or film

Varnish is a clear transparent hard protective coating or film. It is not to be confused with wood stain. It usually has a yellowish shade due to the manufacturing process and materials used, but it may also be pigmented as desired. It is sold commercially in various shades.

<span class="mw-page-title-main">Wood preservation</span> Treatment or process aimed at extending the service life of wood structures

Wood easily degrades without sufficient preservation. Apart from structural wood preservation measures, there are a number of different chemical preservatives and processes that can extend the life of wood, timber, and their associated products, including engineered wood. These generally increase the durability and resistance from being destroyed by insects or fungi.

<span class="mw-page-title-main">Lyocell</span> Regenerated cellulose fiber made from dissolving pulp

Lyocell is a semi-synthetic fiber used to make textiles for clothing and other purposes. It is a form of regenerated cellulose made by dissolving pulp and dry jet-wet spinning. Unlike rayon made by the more common viscose processes, Lyocell production does not use carbon disulfide, which is toxic to workers and the environment. Lyocell was originally trademarked as Tencel in 1982.

<span class="mw-page-title-main">Nafion</span> Brand name for a chemical product

Nafion is a brand name for a sulfonated tetrafluoroethylene based fluoropolymer-copolymer synthesized in 1962 by Dr. Donald J. Connolly at the DuPont Experimental Station in Wilmington Delaware. Additional work on the polymer family was performed in the late 1960s by Dr. Walther Grot of DuPont. Nafion is a brand of the Chemours company. It is the first of a class of synthetic polymers with ionic properties that are called ionomers. Nafion's unique ionic properties are a result of incorporating perfluorovinyl ether groups terminated with sulfonate groups onto a tetrafluoroethylene (PTFE) backbone. Nafion has received a considerable amount of attention as a proton conductor for proton exchange membrane (PEM) fuel cells because of its excellent chemical and mechanical stability in the harsh conditions of this application.

An artificial membrane, or synthetic membrane, is a synthetically created membrane which is usually intended for separation purposes in laboratory or in industry. Synthetic membranes have been successfully used for small and large-scale industrial processes since the middle of the twentieth century. A wide variety of synthetic membranes is known. They can be produced from organic materials such as polymers and liquids, as well as inorganic materials. Most commercially utilized synthetic membranes in industry are made of polymeric structures. They can be classified based on their surface chemistry, bulk structure, morphology, and production method. The chemical and physical properties of synthetic membranes and separated particles as well as separation driving force define a particular membrane separation process. The most commonly used driving forces of a membrane process in industry are pressure and concentration gradient. The respective membrane process is therefore known as filtration. Synthetic membranes utilized in a separation process can be of different geometry and flow configurations. They can also be categorized based on their application and separation regime. The best known synthetic membrane separation processes include water purification, reverse osmosis, dehydrogenation of natural gas, removal of cell particles by microfiltration and ultrafiltration, removal of microorganisms from dairy products, and dialysis.

<span class="mw-page-title-main">Polyester</span> Category of polymers, in which the monomers are joined together by ester links

Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.

<span class="mw-page-title-main">Furfuryl alcohol</span> Chemical compound

Furfuryl alcohol is an organic compound containing a furan substituted with a hydroxymethyl group. It is a colorless liquid, but aged samples appear amber. It possesses a faint odor of burning and a bitter taste. It is miscible with but unstable in water. It is soluble in common organic solvents.

Pultrusion is a continuous process for manufacture of fibre-reinforced plastics with constant cross-section. The term is a portmanteau word, combining "pull" and "extrusion". As opposed to extrusion, which pushes the material, pultrusion pulls the material.

<span class="mw-page-title-main">2-Acrylamido-2-methylpropane sulfonic acid</span> Chemical compound

2-Acrylamido-2-methylpropane sulfonic acid (AMPS) was a Trademark name by The Lubrizol Corporation. It is a reactive, hydrophilic, sulfonic acid acrylic monomer used to alter the chemical properties of wide variety of anionic polymers. In the 1970s, the earliest patents using this monomer were filed for acrylic fiber manufacturing. Today, there are over several thousands patents and publications involving use of AMPS in many areas including water treatment, oil field, construction chemicals, hydrogels for medical applications, personal care products, emulsion coatings, adhesives, and rheology modifiers. Lubrizol discontinued the production of this monomer in 2017 due to copy-cat production from China and India destroying the profitability of this product.

Kebony is a Norwegian wood producer. The company has its roots in Wood Polymer Technologies (WPT), which was founded in 1996 and changed its name to Kebony in 2007. Kebony has a factory in Skien (Norway) and in Antwerp (Belgium).

<span class="mw-page-title-main">Surface modification of biomaterials with proteins</span>

Biomaterials are materials that are used in contact with biological systems. Biocompatibility and applicability of surface modification with current uses of metallic, polymeric and ceramic biomaterials allow alteration of properties to enhance performance in a biological environment while retaining bulk properties of the desired device.

Impregnation resins are slightly viscous, organic liquids that are used in the forest products industry for wood modification. They typically contain formaldehyde and are composed of dimers and trimers of the main molecule. These can become polymer solutions upon curing inside of a wood substrate, imparting stabilizing properties. Impregnation of these resins involves a vacuum chamber procedure that completely disperses the resin into the wood. Once inside of the wood, the resin can diffuse into the cell wall and enhance the physical strength of the wood even further.

<span class="mw-page-title-main">Thermally modified wood</span>

Thermally modified wood is wood that has been modified by a controlled pyrolysis process of wood being heated to (> 180 °C) in an oxygen free atmosphere. This process changes to the chemical structures of wood's cell wall components lignin, cellulose and hemicellulose which increases its durability. Low oxygen content prevents the wood from burning at these high temperatures. Several different technologies are introduced using different media including nitrogen gas, steam and hot oil.

<span class="mw-page-title-main">Wood science</span> The scientific discipline which studies and researches the wood

Wood science is the scientific field which predominantly studies and investigates elements associated with the formation, the physical and chemical composition, and the macro- and microstructure of wood as a bio-based and lignocellulosic material. Wood science additionally delves into the biological, chemical, physical, and mechanical properties and characteristics of wood as a natural material.

Fibre modification is a research field in which researchers aim at developing and applying technologies to impart new properties to natural fibres such as those in paper, in order to increase their functionality. Research areas in this field include many different technologies, amongst which the chemical modifications of fibres are widely used. One important sector of application of the chemical modifications is the treatment of wood for giving it enhanced properties such as higher mechanical properties, water impermeability, less hygroscopicity, bacterial and fungal resistance. Transferring and adapting the technical knowledge on fibre modification available for the wood sector to the recycled paper sector is an innovative use of these chemical treatments which has been the subject of studies that have been carried out within an EU co-funded project called Fibre+.

<span class="mw-page-title-main">Furan resin</span>

Furan resin refers to polymers produced from various furan compounds, of which the most common starting materials are furfuryl alcohol and furfural. In the resin and in the cured polyfurfurol, the furan rings are not connected by conjugation. The resins are generally used as binders for sand castings. The furan monomer is typically converted to a free-flowing resin with mild acid catalysis. Curing is achieved using strong acid.

<span class="mw-page-title-main">Acetylated wood</span> Type of modified wood

Acetylated wood is a type of modified wood that is produced through a chemical modification process and does not contain any toxic substances. It produced from a chemical reaction, involving acetic anhydride and a modification process to make wood highly resistant to biological attacks by fungi and wood-boring insects and durable to environmental conditions. It is a new wood product in the field of wood science, following decades of research and experimentation.

References

  1. ↑ Rowell, R. M. (3 May 2007). "Chemical Modification of Wood". Handbook of Engineering Biopolymers. München: Carl Hanser Verlag GmbH & Co. KG. pp. 673–691. doi:10.3139/9783446442504.022.
  2. ↑ H. Militz, C. Mai (2012). "Other treatment processes". In A. Wagenführ, F. Scholz (ed.). Pocketbook of Wood Technology (2nd, updated ed.). Leipzig: Specialized Book Publisher Leipzig in Hanser Verlag. pp. 485–500. ISBN   978-3-446-42605-4.
  3. ↑ D. Sandberg, A. Kutnar, G. Mantanis (2017). "Wood modification technologies – a review". IForest – Biogeosciences and Forestry. 10 (6): 895–908. doi: 10.3832/ifor2380-010 . ISSN   1971-7458.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. ↑ Mantanis G.I. (2017). "Chemical modification of wood by acetylation or furfurylation: A review of the present scaled-up technologies :: BioResources". BioResources. Retrieved 2023-11-12.
  5. 1 2 Callum A. S. Hill (2006). Wood Modification: Chemical, Thermal and Other Processes. Chichester: John Wiley and Sons. ISBN   0-470-02172-1.
  6. ↑ M. H. Schneider, A. E. Witt (2004). "History of wood polymer composite commercialization". Forest Products Journal: 19–24.
  7. ↑ M. H. Schneider (2001). "Furan polymer impregnated wood". PCT Patent WO 2002/060660 A1, 08.08.2002.
  8. 1 2 3 C. Mai (2010). "Processes of Chemical Wood Modification". Wood Technology. 51. Dresden.
  9. 1 2 Stig Lande, Mats Westin, Marc Schneider (2004-12-01). "Properties of furfurylated wood". Scandinavian Journal of Forest Research. 19 (sup5): 22–30. Bibcode:2004SJFR...19S..22L. doi:10.1080/0282758041001915. ISSN   0282-7581. S2CID   85421359.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  10. 1 2 P. Brynildsen, R. Bendiktsen, F. Englund, C. A. S. Hill, H. Militz, B. K. Segerholm (2009). B. K. Segerholm (ed.). State-of-the-art Kebony factory and its main products. Proc. of the 4th European conference on wood modification. Stockholm. pp. 37–42.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: multiple names: authors list (link)
  11. ↑ Philippe Gérardin (2016-09-01). "New alternatives for wood preservation based on thermal and chemical modification of Wood – a review". Annals of Forest Science. 73 (3): 559–570. doi: 10.1007/s13595-015-0531-4 . ISSN   1286-4560. S2CID   256205301.
  12. ↑ M. Westin, P. Larsson-Brelid, T. Nilsson, A. Rapp, J. P. Dickerson, S. Lande, S. Cragg (May 2016). "Marine borer resistance of acetylated and furfurylated wood – Results from up to 16 years of field exposure". Proceedings of the "47th Annual Meeting of the International Research Group (IRG) on Wood Protection". Stockholm: 10ff.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  13. ↑ Philippe Gérardin (2016-09-01). "New alternatives for wood preservation based on thermal and chemical modification of wood— a review". Annals of Forest Science. 73 (3): 559–570. doi: 10.1007/s13595-015-0531-4 . ISSN   1286-4560. S2CID   256205301.
  14. ↑ Lin, Chia-feng; Kim, Injeong; Mantanis, George I.; Karlsson, Olov; Jones, Dennis; Sandberg, Dick (2021-11-02). "Leach-resistant fire-retardant treated furfurylated wood by incorporating guanyl-urea phosphate". Wood Material Science & Engineering. 16 (6): 429–431. doi:10.1080/17480272.2021.1981998. ISSN   1748-0272.
  15. ↑ Dong, Youming; Fu, Zhenyu; Yan, Yutao; Shi, Jingbo; Hughes, Mark; Zhan, Xianxu; Li, Jianzhang (2024). "Improving the flame retardancy of furfurylated wood by introducing DOPO". Wood Science and Technology. 58 (1): 273–293. doi:10.1007/s00226-023-01513-2. ISSN   0043-7719.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.