Assessment of plastic lumber production in Brazil as a substitute for natural wood

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

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

Download Full-text

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.

Download Full-text

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.

Download Full-text

Geomorphological numerical modelling of woody dams in CAESAR-Lisflood

10.5194/egusphere-egu21-9636 ◽

2021 ◽

Author(s):

Josh Wolstenholme ◽

Christopher Skinner ◽

David Milan ◽

Daniel Parsons

Keyword(s):

Flood Risk ◽

Flood Management ◽

River Channels ◽

Sensitivity Testing ◽

Spatial And Temporal Scales ◽

Natural Processes ◽

Natural Wood ◽

Long Term Impact ◽

Morphology Influence

Natural flood management (NFM) promotes the sustainable enhancement of natural fluvial processes to reduce flooding (SEPA, 2015; Wilkinson et al., 2019), and is increasingly popular for use by community groups, contractors and governments (Kay et al., 2019). Reintroduction of wood to a river channel is a popular form of NFM often achieved through seeding natural logjams, or with an emphasis on engineering through installing woody dams (WDs). WDs are currently installed or being installed in catchments in an effort to reduce flood risk, through hydrograph attenuation, increase biodiversity and improve geomorphic heterogeneity (Wenzel et al., 2014; Burgess-Gamble et al., 2017; Grabowski et al., 2019). A further objective is to emulate the effect of natural wood found in river channels by partially, or completely, blocking the channel to accelerate the recruitment of natural wood as part of the natural wood cycle (Addy & Wilkinson, 2016).There is a growing body of evidence supporting the benefits of NFM, however, the hydrogeomorphic effects of WDs are less well understood (Dadson et al., 2017). There is little scientific underpinning concerning the long-term impact of these features upon hydrogeomorphology at reach and catchment-scales. Very few numerically based studies consider the influence of sediment transport on WDs, and how changes in local bed morphology influence their effectiveness. Most NFM research to date has focused upon modelling the effectiveness of local NFM measures in small catchments (<10 km2) (Dadson et al., 2017), with less work evident at larger spatial and temporal scales (Kay et al., 2019; Wilkinson et al., 2019).There is a need for a verified tool that is able to represent WDs accounting for geomorphic processes and interactions between the dams and morphodynamics, different design specifications of dams, and changing efficacy due to geomorphic evolution. We present the new CAESAR-Lisflood (Coulthard et al., 2013) &#8220;Working with Natural Processes&#8221; toolkit, capable of representing WDs across a digital experimental environment. Global sensitivity testing was conducted using the Morris method (Morris, 1991) to assess the sensitivity of five aspects of the toolkit, and their potentially influences on geomorphology and flood risk reduction.

Download Full-text

THE USE OF NANOSCALE ZINC OXIDE IN WOOD-BASED COMPOSITIONS

10.34220/mmeitsic2021_256-260 ◽

2021 ◽

Author(s):

S. Neminushchaya ◽

E. Tomina ◽

A. Dmitrenkov

Keyword(s):

Zinc Oxide ◽

Vegetable Oil ◽

Zinc Oxide Nanoparticles ◽

Sol Gel ◽

Environmental Safety ◽

Oxide Nanoparticles ◽

Natural Wood ◽

Oxide Particles ◽

Used Vegetable Oil ◽

20 Nm

The aim of this work was to study compositions based on vegetable oil waste and nanoscale zinc oxide particles for processing natural wood. The sol-gel method was used for the synthesis of zinc oxide nanoparticles. The synthesized zinc oxide nanoparticles did not contain impurities and had a shape close to spherical, and their size did not exceed 20 nm. We used freshly prepared suspensions of zinc oxide nanoparticles in used vegetable oil with their content in the amount of 0.1, 0.5 and 1.0 wt. parts per 100 parts of oil. The wood was treated by hot-cold impregnation. The tests were carried out on samples of birch and pine wood of standard sizes. In the modified samples, the wetting angle, moisture and water absorption, as well as their swelling were determined. It is shown that the use of zinc oxide nanoparticles in compositions based on vegetable oil waste can significantly reduce the moisture and water resistance of wood and reduce its swelling. The optimal dosages of the nanopowder introduced into the used vegetable oil and the conditions of impregnation were selected. The compositions used on the basis of vegetable oil waste are characterized by environmental safety, and the resulting wood samples had an improved appearance.

Download Full-text