A strong multilayered transparent wood with natural wood color and texture

Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.

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Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽

10.3390/polym13020220 ◽

2021 ◽

Vol 13 (2) ◽

pp. 220

Author(s):

Petar Antov ◽

Viktor Savov ◽

Ľuboš Krišťák ◽

Roman Réh ◽

George I. Mantanis

Keyword(s):

Mechanical Properties ◽

Bending Strength ◽

Urea Formaldehyde ◽

Physical And Mechanical Properties ◽

High Density ◽

Thickness Swelling ◽

Formaldehyde Content ◽

Uf Resin ◽

Natural Wood ◽

European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

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Wood Color Classification Based on Color Spatial Features and K-means Algorithm

IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society ◽

10.1109/iecon43393.2020.9255104 ◽

2020 ◽

Author(s):

Ye Lin ◽

Dan Chen ◽

Shijia Liang ◽

Yang Qiu ◽

Zhezhuang Xu ◽

...

Keyword(s):

Color Classification ◽

Wood Color ◽

Spatial Features

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EFICIÊNCIA DE EXTRATO TÂNICO COMBINADO OU NÃO COM ÁCIDO BÓRICO NA PROTEÇÃO DA MADEIRA DE Ceiba pentandra CONTRA CUPIM XILÓFAGO

FLORESTA ◽

10.5380/rf.v44i1.28798 ◽

2014 ◽

Vol 44 (1) ◽

pp. 43 ◽

Cited By ~ 1

Author(s):

Leandro Calegari ◽

Pedro Jorge Goes Lopes ◽

Gregório Mateus Santana ◽

Diego Martins Stangerlin ◽

Elisabeth De Oliveira ◽

...

Keyword(s):

Boric Acid ◽

Sodium Sulfite ◽

Condensed Tannin ◽

Acid Leaching ◽

Distilled Water ◽

Ceiba Pentandra ◽

Nasutitermes Corniger ◽

Natural Wood ◽

Vegetable Tannins ◽

Mimosa Tenuiflora

Dentre os métodos que vêm sendo testados para minimizar a lixiviação de compostos de boro na madeira, destaca-se sua combinação com taninos vegetais. Aos taninos vegetais é atribuída a durabilidade natural da madeira de algumas espécies, indicando sua potencialidade como preservativo natural. Neste estudo, avaliou-se o rendimento de taninos condensados provenientes da casca de Mimosa tenuiflora em extração realizada com água destilada, comparando-o ao da extração envolvendo a inclusão de sulfito de sódio, assim como a eficiência de extratos tânicos sulfitados, combinados ou não com ácido bórico, na melhoria da resistência da madeira de Ceiba pentandra ao térmita xilófago Nasutitermes corniger, por meio de ensaio de preferência alimentar. Extrato tânico obtido com a inclusão de sulfito de sódio à água teve melhor rendimento em taninos condensados. De maneira geral, a impregnação da madeira com o extrato tânico sulfitado proporcionou o mesmo comportamento quando comparada à aplicação do ácido bórico, sendo os melhores resultados verificados quando ambos foram utilizados conjuntamente. No entanto, depois de aplicado na madeira, o extrato tânico foi lixiviado e não favoreceu a redução da lixiviação do ácido bórico. Apesar da potencialidade do uso do extrato tânico ao cupim xilófago, estudos adicionais fazem-se necessários.Palavras-chave: Biodeterioração da madeira; térmitas xilófagos; Nasutitermes corniger. AbstractTannic extract efficiency combined or not with boric acid on protection of Ceiba pentandra wood against xylophagous termite. Among the methods tested to reduce the leaching of boron compounds in wood, it can be highlighted their combination with vegetable tannins. It is attributed the natural durability of some species of wood to vegetable tannins, pointing to their potentiality as natural wood preservatives. This research evaluated the efficiency of condensed tannins from bark of Mimosa tenuiflora extract with distilled water, compared to another extract added of sodium sulfite. It also evaluated the efficiency of sulfited tannin extracts, combined or not with boric acid in order to improve the resistance of Ceiba pentandra against the xylophagous termite Nasutitermes corniger by feeding test. Tannic extract obtained by adding sodium sulfite to distilled water revealed better yield compared to condensed tannin extraction. In general, impregnation of wood with tannin extract presented the same behavior as compared to application of boric acid, with best results observed when both them were simultaneously used. However, after applied to wood, tannin extracted was leachable and it did not favor the boric acid leaching. Despite the potential use of tannic extract against the xylophagous termite, additional studies are required for a best evaluation.Keywords: Wood biodeterioration; xilophogous termites; Nasutitermes corniger.

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Comparison of rice husk-filled polyethylene composite and natural wood under weathering effects

Journal of Composite Materials ◽

10.1177/0021998310381545 ◽

2010 ◽

Vol 45 (13) ◽

pp. 1403-1410 ◽

Cited By ~ 21

Author(s):

W.A.W.A. Rahman ◽

Lee Tin Sin ◽

A.R. Rahmat ◽

N.M. Isa ◽

M.S.N. Salleh ◽

...

Keyword(s):

Rice Husk ◽

Polyethylene Composite ◽

Natural Wood ◽

Weathering Effects

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Chemical improvement of surfaces. Part 3: Covalent modification of Scots pine sapwood with substituted benzoates providing resistance to Aureobasidium pullulans staining fungi

Holzforschung ◽

10.1515/hf-2014-0086 ◽

2015 ◽

Vol 69 (5) ◽

pp. 595-601 ◽

Cited By ~ 4

Author(s):

Jan C. Namyslo ◽

Dieter E. Kaufmann ◽

Carsten Mai ◽

Holger Militz

Keyword(s):

Scots Pine ◽

Aureobasidium Pullulans ◽

Covalent Modification ◽

Attenuated Total Reflection ◽

Chemically Modified ◽

Covalently Bonded ◽

Blue Stain ◽

Natural Wood ◽

The Individual ◽

Modified Wood

Abstract The development of appropriate chemical precursors that can covalently functionalize natural wood aims at efficient restriction of deterioration. Biological staining experiments were performed with veneer pieces made of sapwood of Scots pine (Pinus sylvestris L.) that had previously been chemically modified with substituted benzoates. Based on the recently published protocol on esterification of wood by means of 1H-benzotriazole activation, the quantity of covalently bonded organomaterials (QCOs), a recently defined advantageous value considering the individual molecular weight of the functionalizing organochemical groups, was obtained in the range of 0.9–1.5 mmol g-1. The modified wood was analyzed by attenuated total reflection IR spectroscopy. Modification with three electronically different benzoates clearly reduced the colonization of the specimen’s surfaces by the blue stain fungus Aureobasidium pullulans but did not fully prevent it. The degree of colonization appeared to decrease with increasing QCO values of the modification agents but apparently did not strongly depend on the additional functionality of the benzoate.

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A top-down approach making cellulose carbonaceous aerogel/MnO2 ultrathick bulk electrodes with high mass loading for supercapacitors

Materials Chemistry Frontiers ◽

10.1039/d1qm00286d ◽

2021 ◽

Author(s):

Weiye Zhang ◽

Yanchen Li ◽

Beibei Wang ◽

Jingmeng Sun ◽

Lin Lin ◽

...

Keyword(s):

Porous Carbon ◽

High Mass ◽

Mass Loading ◽

Top Down ◽

Thin Walled Tube ◽

Natural Wood ◽

Thin Walled ◽

Array Structure

A cellulose carbonaceous aerogel/MnO2 ultrathick electrode with a unique low curvature, porous carbon thin-walled tube array structure was obtained from natural wood using a simple top-down approach.

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Comparison of the color and weight change in Paulownia tomentosa and Pinus koraiensis wood heat-treated in hot oil and hot air

BioResources ◽

10.15376/biores.16.3.5574-5585 ◽

2021 ◽

Vol 16 (3) ◽

pp. 5574-5585

Author(s):

Intan Fajar Suri ◽

Jong Ho Kim ◽

Byantara Darsan Purusatama ◽

Go Un Yang ◽

Denni Prasetia ◽

...

Keyword(s):

Heat Treatment ◽

Color Change ◽

Treated Wood ◽

Pinus Koraiensis ◽

Weight Changes ◽

Paulownia Tomentosa ◽

Wood Color ◽

Color Changes ◽

Hot Air ◽

Heat Treated

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.

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