Preservation, Protection, and Modification of Wood and Wood Byproducts

A special issue of Forests (ISSN 1999-4907). This special issue belongs to the section "Wood Science and Forest Products".

Deadline for manuscript submissions: closed (30 November 2023) | Viewed by 18847

Special Issue Editors


E-Mail Website
Guest Editor
1. ARCP-Associação Rede de Competência em Polímeros, 4200-355 Porto, Portugal
2. LEPABE-Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal
Interests: wood-based products; bioadhesives; adhesives; polymers; polyphenols; lignocellulosic byproducts valorization; dyeing; packaging
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
1. Unidad de Desarrollo Tecnológico, Universidad de Concepción, Coronel 4191996, Chile
2. Centro Nacional de Excelencia para la Industria de la Madera (CENAMAD), Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago 7820436, Chile
Interests: chemical Analysis; chemical Processes; agricultural biotechnology phytochemicals; bioactivity; natural product chemistry; mass spectrometry
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

In these times of change due to the international global crisis, the sources of energy and raw materials are and will be one of the main industrial and social concerns of the future.

The scientific community is focused on studying new ways of obtaining energy and products using more sustainable processes with less environmental impact. For this, it is important to develop processes that reduce energy consumption and waste production and increase the final value of the products obtained.

In this context, reducing dependence on fossil fuels is one of the great challenges of the near future. Wood and wood byproducts, along with other lignocellulosic byproducts, are the main alternatives to the use of petrochemicals in the development of new, more sustainable biomaterials. However, it is necessary to understand that wood is a renewable raw material with a limited production capacity. It is necessary, together with the continuous improvement of forestry and industrial wood production processes, to develop new productive treatment processes that allow the obtaining of wood-based final products that meet the requirements that industry and society demand.

This Special Issue of Forests aims to collect recent results from field experimental observations and laboratory studies at various sites around the world, as well as related meta-analysis and modeling studies, which would improve the valorization of wood and wood byproducts.

We invite submissions for a special issue of Forests on the subject of “Preservation, Protection, and Modification of Wood and Wood Byproducts”. Topics for submissions may include but not be limited to:

  • Preservation of wood;
  • UV/VIS protection for wood;
  • Antifungal treatment for wood;
  • Paints, coatings, and pigments from or for wood;
  • Modification of forest lignocellulosic byproducts;
  • Extractives and biopolymers from wood;
  • Non-timber wood applications;
  • Forest biorefinery;
  • Fibers from wood and wood byproducts;
  • Wood recycling and reuse;
  • Fast-growing crops as wood alternatives.

Dr. Jorge Santos
Dr. Danilo Escobar-Avello
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Forests is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • polyphenols
  • tannins
  • lignin
  • cellulose
  • hemicellulose
  • wood extractives
  • wood chemistry
  • biocomposites
  • chemical modification
  • esterification
  • acetylation
  • wood preservation
  • biorefinery
  • wood bark
  • fungal protection
  • biocides
  • UV/VIS
  • FITR
  • mass spectrometry
  • bioadhesives
  • wood treatment
  • particleboards
  • plywood
  • wood-based panels
  • recyclability

Published Papers (10 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

14 pages, 4706 KiB  
Article
Preparation and Characterization of Wood Composites for Wood Restoration
by Tianyuan Chen, Qichao Ma, Yudong Li and Guoliang Li
Forests 2023, 14(9), 1743; https://doi.org/10.3390/f14091743 - 28 Aug 2023
Cited by 2 | Viewed by 1137
Abstract
Given the widespread use of wood-based materials and that these materials are often damaged, an abundance of materials have been developed to repair and restore wood. Most of these materials treat the binder and filler as a single system; however, there is yet [...] Read more.
Given the widespread use of wood-based materials and that these materials are often damaged, an abundance of materials have been developed to repair and restore wood. Most of these materials treat the binder and filler as a single system; however, there is yet to be a system that has all the desired properties of an ideal wood-repair composite. Aiming for the goal of creating an ideal wood filler, this study proposed a wood-repair composite that combined epoxy resins, polyether amines, and poplar wood fibers. The materials were selected to mimic the hydrophobicity of lotus leaves and the strong adhesion of mussel proteins. The properties of the designed wood composites were characterized by various testing methods. The prepared fillers were then used to repair damaged poplar wood panels. The mechanical properties of the wood sample repaired with the optimal filler formulation reached 97% of those of the undamaged wood. In summary, the wood composites proposed in this study present a new means of repairing wooden relics, exposed outdoor wooden buildings, and household panels. Full article
Show Figures

Figure 1

14 pages, 2447 KiB  
Article
The Viscoelastic and Hygroscopicity Behavior of Delignified and Densified Poplar Wood
by Jiajun Wang, Yubo Chai, Junliang Liu and J.Y. Zhu
Forests 2023, 14(9), 1721; https://doi.org/10.3390/f14091721 - 26 Aug 2023
Cited by 1 | Viewed by 1324
Abstract
The combination of alkaline delignification and densification was applied to improve wood mechanical strength. Poplar wood samples were subjected to alkali delignification with varying degrees of lignin and hemicellulose removal followed by hot pressing. Dynamic mechanical performances and dynamic sorption behavior of the [...] Read more.
The combination of alkaline delignification and densification was applied to improve wood mechanical strength. Poplar wood samples were subjected to alkali delignification with varying degrees of lignin and hemicellulose removal followed by hot pressing. Dynamic mechanical performances and dynamic sorption behavior of the untreated and densified wood were then evaluated. Results showed that appropriate removal of lignin can improve the stiffness of densified wood and reduce moisture sorption and the numbers of sorption sites. Fourier transform infrared (FTIR) microscopy along with X-ray diffraction (XRD) were used to explain the viscoelastic and hygroscopicity of delignified and densified wood. Hemicelluloses and lignin were selectively dissolved during alkali treatment. Wood crystallinity was increased after alkali treatment at a moderate concentration of 2%, beneficial to improving the dimensional stability and mechanical performance of delignified and densified wood. The crosslinking of cellulose chains through hydrogen bonding, the decreased content of free hydroxyl groups, and the increased crystallinity in the cell wall contributed to higher storage modulus and lower hydrophilicity. The results support mild delignification and densification as a feasible way towards extending the service life of wood products used as structural materials. Full article
Show Figures

Figure 1

13 pages, 2684 KiB  
Article
Fungal Colonization of Weathered Radiata Pine Surfaces Protected with Inorganic Nanoparticles and Coatings
by Vicente A. Hernandez, Nicole Sagredo, Javiera Riquelme, Romina Romero and Philip D. Evans
Forests 2023, 14(7), 1338; https://doi.org/10.3390/f14071338 - 29 Jun 2023
Viewed by 1041
Abstract
Photoactive nanoparticles are used to reduce microbial colonization and self-clean surfaces of materials such as glass and ceramics. To test whether such an approach is feasible for wood surfaces, we treated radiata pine samples with TiO2 (rutile and anatase) or ZnO nanoparticles [...] Read more.
Photoactive nanoparticles are used to reduce microbial colonization and self-clean surfaces of materials such as glass and ceramics. To test whether such an approach is feasible for wood surfaces, we treated radiata pine samples with TiO2 (rutile and anatase) or ZnO nanoparticles and then coated the samples with different finishes. Coated samples and uncoated controls were exposed outdoors for six months. After exposure, fungi colonizing wood surfaces were identified using molecular techniques and microscopy, and colour changes in the wood samples were also measured. Treatment of uncoated surfaces with nanoparticles reduced the discolouration of wood during weathering but had little effect on colonization of wood by black mould fungi. In contrast, pretreatment of samples with titanium dioxide nanoparticles increased the number and diversity of fungi including basidiomycetes colonizing coated samples, whereas zinc oxide nanoparticles had the opposite effect. Zinc oxide nanoparticles, however, were less effective than rutile titanium dioxide nanoparticles at reducing the discolouration of coated samples exposed to natural weathering. We conclude that none of the photoactive nanoparticles on their own are able to reduce microbial colonization and discoloration of samples. This suggests that it may be difficult to create self-cleaning wood surfaces using photoactive nanoparticles. Full article
Show Figures

Figure 1

19 pages, 3098 KiB  
Article
Valorization of Uruguayan Pinus elliottii Bark by Developing Sustainable Adhesives
by Paola Serrentino, Jorge Santos, Cecilia Fuentealba, Laidy Hernandez-Mena, Alvaro Mary and Claudia Marcela Ibañez
Forests 2023, 14(6), 1184; https://doi.org/10.3390/f14061184 - 8 Jun 2023
Viewed by 1263
Abstract
Pinus elliottii Engelm bark is a byproduct of Uruguay’s milling industry. As a circular economy strategy, it is burned in broilers for energy production. Aiming to increase the added value of the bark, this work analyzes the extraction of its tannins to use [...] Read more.
Pinus elliottii Engelm bark is a byproduct of Uruguay’s milling industry. As a circular economy strategy, it is burned in broilers for energy production. Aiming to increase the added value of the bark, this work analyzes the extraction of its tannins to use them in the development of formaldehyde-free adhesives, while evaluating whether it retains its calorific power for further energy production. The best extraction conditions (methanol at 65 °C for 2 h) were identified at a laboratory level after which they were scaled up to 50 L, which did not affect extraction yield. The Stiasny number remained above 65%, meaning the extractive was suitable for its use in adhesive formulations. The characterization of the extractives was completed with molecular weight distribution, FTIR-ATR, ABES and DSC. Finally, two formaldehyde-free adhesive formulations were developed using hexamine and glyoxal as hardeners. Their behaviors were compared through rheological analysis, DSC and ABES. It was determined that the adhesive formulations with hexamine at pHs of 8 and 10 are suitable for their use in the timber industry. It was noted that they react the best at a pressing temperature of 160 °C. After the extraction, the calorific power of the P. elliottii Engelm bark decreased by only 13%, thus remaining useful for energy production. Full article
Show Figures

Figure 1

14 pages, 2754 KiB  
Article
Ammoniacal Zinc Borate for Wood Protection against Fungi and Insects
by Claudia Marcela Ibáñez, Guillermo Katzenstein, Carlos Mantero, Valentina Benítez, Alvaro Camargo, Natalia Berberian and Martin Bollazzi
Forests 2023, 14(6), 1152; https://doi.org/10.3390/f14061152 - 2 Jun 2023
Cited by 2 | Viewed by 1311
Abstract
The organic nature of wood makes it susceptible to abiotic and biotic degradation. Impregnation with chemical products is the most common method of protection. Only inorganic borates combine the unique set of properties that make them well suited for wood protection: they are [...] Read more.
The organic nature of wood makes it susceptible to abiotic and biotic degradation. Impregnation with chemical products is the most common method of protection. Only inorganic borates combine the unique set of properties that make them well suited for wood protection: they are insecticidal, fungicidal and flame retardants. In this work, zinc borate is suspended in an ammonia solution and applied in depth to wood. Its resistance to leaching is evaluated. The product is tested against rot fungi (Gloeophyllum trabeum and Trametes versicolor) and a xylophagous insect (Anobium punctatum). The results verify its effectiveness as a wood protector, while leaching less than other borate-based products. Full article
Show Figures

Figure 1

21 pages, 2573 KiB  
Article
Pretreated Eucalyptus globulus and Pinus radiata Barks: Potential Substrates to Improve Seed Germination for a Sustainable Horticulture
by Danilo Escobar-Avello, Víctor Ferrer, Gastón Bravo-Arrepol, Pablo Reyes-Contreras, Juan P. Elissetche, Jorge Santos, Cecilia Fuentealba and Gustavo Cabrera-Barjas
Forests 2023, 14(5), 991; https://doi.org/10.3390/f14050991 - 11 May 2023
Cited by 4 | Viewed by 2606
Abstract
Commercial forest plantations in Chile are dominated by pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). Tree bark is the main by-product of the forestry industry and has low value, but great potential for use as an agricultural substrate. However, [...] Read more.
Commercial forest plantations in Chile are dominated by pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). Tree bark is the main by-product of the forestry industry and has low value, but great potential for use as an agricultural substrate. However, the direct use of bark fibers may cause plant phytotoxicity due to the presence of polyphenolic and other compounds. This study aims to evaluate the physicochemical properties of E. globulus and P. radiata bark after water extraction treatments. The phytotoxicity of the resulting extracted bark alone and that mixed with commercial substrates (coconut fiber, moss, peat, and composted pine) at different ratios (25 to 75 wt%) were assessed using the Munoo-Liisa vitality index (MLVI) test. For all treatments, the seed germination and growth of radish (Raphanus sativus) and Chinese cabbage (Brassica rapa) species were evaluated and compared to a commercial growing medium (peat) as a control. The optimal mixture for seed growth was determined to be 75% extracted E. globulus bark fiber and 25% commercial substrates such as peat (P), coconut fiber (C), moss (M), and composted pine (CP), as indicated by the MLVI and germination results. Two phytostimulant products, chitosan and alginate-encapsulated fulvic acid, were added to the best substrate mixture, with the purpose of improving their performance. Encapsulated fulvic acid at 0.1% w/v was effective in promoting plant growth, while chitosan at all of the concentrations studied was effective only for mixture 75E-25CP. The mixture of E. globulus fiber and commercial substrates, containing a high proportion of water-extracted fiber (75%), shows the potential to be used in the growth of horticultural crops and in the plant nursery industry. Full article
Show Figures

Graphical abstract

20 pages, 4173 KiB  
Article
Forest by-Product Valorization: Pilot-Scale Pinus radiata and Eucalyptus globulus Bark Mixture Extraction
by Jorge Santos, Danilo Escobar-Avello, Cecilia Fuentealba, Gustavo Cabrera-Barjas, Julia González-Álvarez, Jorge M. Martins and Luisa H. Carvalho
Forests 2023, 14(5), 895; https://doi.org/10.3390/f14050895 - 26 Apr 2023
Cited by 1 | Viewed by 2568
Abstract
One of the most important by-products generated in the forestry industry is the bark obtained during the debarking process. Pine (Pinus radiata D. Don) and eucalyptus (Eucalyptus globulus L.) are the main important tree species exploited in the Chilean forestry industry. [...] Read more.
One of the most important by-products generated in the forestry industry is the bark obtained during the debarking process. Pine (Pinus radiata D. Don) and eucalyptus (Eucalyptus globulus L.) are the main important tree species exploited in the Chilean forestry industry. The bark of P. radiata D. Don is an interesting source of extracts, rich in condensed tannins, with potential uses in biopolymer and bioadhesive preparation. Conversely, the E. globulus bark extracts are rich in hydrolyzable tannins with few applications. Nevertheless, the forest industry generates a high volume of these by-products, simultaneously. Then, it is interesting to determine a suitable process for the joint valorization of both forest by-products at a large scale. In this work, alkaline extraction (NaOH and Na2SO3) was performed at a pilot scale of a mixture of E. globulus and P. radiata barks prepared at different ratios (0%–100%). The effect of bark mixture composition on the resulting extract’s properties was evaluated. All extracts were characterized according to their chemical composition by FTIR-ATR, MALDI-TOF, and molecular weight distribution (GPC). In addition, the Stiasny number was tested to determine the potential use of extracts in bioadhesive formulation. The self-condensation reaction of resulting extracts was studied using Dynamic Mechanical Analysis (DMA) and Automated Bond Evaluation System (ABES) techniques. Results show a good interaction between condensed and hydrolyzable tannins from both species’ barks. It also demonstrated the potential application of the obtained extracts, for a bark ratio of 50:50, in the formulation of bioadhesives for particleboard manufacture. The obtained product showed a similar performance to that of the bioadhesive formulated with the extract obtained using only P. radiata bark. Full article
Show Figures

Figure 1

16 pages, 7600 KiB  
Article
Studies of the Photoprotection of Radiata Pine Wood Using Photocatalytic Nanoparticles
by Vicente A. Hernandez, Romina Romero, Nicole Sagredo, David Contreras and Philip D. Evans
Forests 2022, 13(11), 1922; https://doi.org/10.3390/f13111922 - 16 Nov 2022
Cited by 3 | Viewed by 1923
Abstract
In this work, TiO2 and ZnO nanoparticles of different sizes and crystallographic configuration were used to protect wood surfaces against UV radiation. The sizes and levels of photoactivity of the nanoparticles were measured in vitro by transmittance electron microscopy and electron paramagnetic [...] Read more.
In this work, TiO2 and ZnO nanoparticles of different sizes and crystallographic configuration were used to protect wood surfaces against UV radiation. The sizes and levels of photoactivity of the nanoparticles were measured in vitro by transmittance electron microscopy and electron paramagnetic resonance spectroscopy, and then they were impregnated into radiata pine samples. The production of aromatic radicals, absorbance of UV and visible light, and chemical and color changes of treated and untreated wood surfaces were assessed after UV irradiation. Results show that nanoparticles that were less photoactive were better at reducing the production of organic radicals and the chemical and color changes on wood surfaces subjected to UV. Similarly, smaller nanoparticles (40 nm) were better at reducing photochemical reactions than larger (100 nm) nanoparticles. In terms of the crystallographic configuration of nanoparticles, differences in the production of phenoxy radicals were verified only for short-term exposure. Previous research revealed that certain levels of photoactivity in TiO2 nanoparticles may contribute to decreases in the photodegradation of wood surfaces possibly by an electron sink mechanism. Our observations indicate that this is unlikely to occur in the presence of highly photoactive nanoparticles. Full article
Show Figures

Figure 1

12 pages, 2068 KiB  
Article
Analyses of Impregnation Quality and Mechanical Properties of Radiata Pine Wood Treated with Copper Nanoparticle- and Micronized-Copper-Based Wood Preservatives
by María Graciela Aguayo, Oswaldo Erazo, Claudio Montero, Laura Reyes, William Gacitúa, Liset Gómez and Hugo Torres
Forests 2022, 13(10), 1636; https://doi.org/10.3390/f13101636 - 6 Oct 2022
Cited by 3 | Viewed by 1964
Abstract
In this work, the impregnation quality and mechanical properties of Pinus radiata D.Don treated with different copper nanoparticles (CuNP) solutions (named K1 and K2) and a commercial preservative (M) were studied. The impregnation quality of radiata pine wood was analyzed by two indicators, [...] Read more.
In this work, the impregnation quality and mechanical properties of Pinus radiata D.Don treated with different copper nanoparticles (CuNP) solutions (named K1 and K2) and a commercial preservative (M) were studied. The impregnation quality of radiata pine wood was analyzed by two indicators, penetration and retention. The micro-distribution of preservative in the treated wood was qualitatively evaluated by SEM-EDS, both in the samples containing CuNP and in those treated with the commercial preservative. In addition, some mechanical properties were studied in the preserved wood including MOE, MOR and hardness. The results indicated values by ED XRF retention of 0.96 kg/m3 and 0.86 kg/m3 for K1 and K2, respectively, and 1.01 kg/m3 for M wood impregnated. In the penetration determined by colorimetric test, the wood samples impregnated (with K1, K2 and M) showed 100% penetration. The distribution of CuNP and micronized copper within the wood structure was confirmed by SEM EDS mapping. In mechanical properties, a reduction in MOE was reflected in all wood treated. The control samples were far superior to the K1 and M treated samples and slightly superior to the K2 samples, with no statistically significant differences. On the other hand, samples impregnated with K1 and K2 showed the highest values in hardness parallel and perpendicular to the grain, revealing that these preservative solutions tend to increase hardness. Overall, when it comes to the samples impregnated with micronized copper (M), the mechanical properties were considerably lower compared to the CuNP treated and control wood. Therefore, the CuNP-based preservative did not strongly affect the mechanical properties of the preserved wood. Full article
Show Figures

Figure 1

14 pages, 5443 KiB  
Article
Antifungal Activity of Datura stramonium L. Extractives against Xylophagous Fungi
by Jessica Esmeralda Vega-Ceja, Rosa María Jiménez-Amezcua, José Anzaldo-Hernández, José Antonio Silva-Guzmán, José Guillermo Torres-Rendón, María Guadalupe Lomelí-Ramírez and Salvador García-Enriquez
Forests 2022, 13(8), 1222; https://doi.org/10.3390/f13081222 - 2 Aug 2022
Viewed by 2117
Abstract
Some plants have great resistance against herbivores, invertebrates, insects, bacteria, and fungi. This resistance is mostly present in plants containing alkaloids, which are the substances responsible for giving them defensive properties. The genus Datura contains tropane alkaloids and all plants from this genus [...] Read more.
Some plants have great resistance against herbivores, invertebrates, insects, bacteria, and fungi. This resistance is mostly present in plants containing alkaloids, which are the substances responsible for giving them defensive properties. The genus Datura contains tropane alkaloids and all plants from this genus have defensive properties. In this work, we report the toxic effect against fungi of Datura stramonium extracts, obtained by the Petri dish method. The extraction solvents were water, ethanol, 2-propanol, n-butanol, propanone, butanone, 3-methyl-2-pentanone, dichloromethane, xylene, and toluene. The test fungi were Trametes versicolor (L. ex. Fr) Pilát and Rhodonia placenta (Fr.) Niemelä, K.H.Larss. & Schigel. It was found that water, butanone, and toluene extracts promoted mycelial growth, xylene extracts neither inhibited nor promoted mycelial growth, while the other extracts slightly inhibited the growth of these fungi. Full article
Show Figures

Figure 1

Back to TopTop