Enhancing mechanical properties of particleboards using plasma treated wood particles

Recent trends in lightweight concrete manufacturing have led to a proliferation of studies demonstrating that wood aggregates can be used to produce sustainable green concrete composites. However, wood particles contain soluble substances (saccharides), which have a significant effect on the setting time of Portland cement. To attain a better understanding of this, two types of wood were treated in boiling water. After the treatment process, the resulting water (“boiling water of wood”) was used to study its effect on the initial setting time of Portland cement. The mechanical properties and the density were also investigated for concrete mixtures consisting of 0, 5, 7.5, and 10% treated wood particles (weight replacement from coarse aggregate). As a result, the effect of the wood’s soluble substances was determined and the optimum mix proportion was chosen for achieving the minimum nominal density and the best mechanical properties.

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Enhancement of the properties of hybrid woods polymer composites by chemical pre-treatments

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420720980033 ◽

2020 ◽

pp. 146442072098003

Author(s):

Mohammad ZR Khan ◽

Sunil Kumar Srivastava ◽

MK Gupta

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Water Resistance ◽

Treated Wood ◽

Wood Composites ◽

X Ray Diffraction ◽

Absorption Properties ◽

Shorea Robusta ◽

Wood Particles ◽

Maximum Water

The present work aims to enhance the mechanical properties, thermal stability, and water resistance behavior of hybrid Pinus/Shorea robusta wood particles reinforced epoxy composites employing the chemical pre-treatments. The hybrid wood composites were prepared by hand lay-up method keeping a constant of 25 wt% of wood particles concentration with equal proportions of Pinus and Shorea robusta wood particles. The performance of the hybrid wood composite was improved by improving the interfacial bonding between wood particles and epoxy resin by chemical pre-treatments of the wood particles using silane (APTES) with varying concentrations of 2, 4, and 6 wt% and alkali (NaOH) with varying concentrations of 5%, 10%, and 15%. The mechanical properties (namely, tensile, flexural, impact, and microhardness) and water absorption properties (namely, maximum water uptake and sorption, diffusion, and permeability coefficients) of the prepared hybrid wood composites were measured. The investigations include the study of thermal degradation and crystalline behavior using thermogravimetric analysis and X-ray diffraction analysis, respectively. It was observed that the mechanical properties, thermal stability, and water resistance and crystalline behavior of the hybrid wood composites were significantly enhanced after these pre-treatments. Further, it was concluded that silane pre-treated hybrid composite with 6 wt% concentration provided the best performance than untreated as well as alkali pre-treated wood composites.

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Temperature-Dependent Creep Behavior and Quasi-Static Mechanical Properties of Heat-Treated Wood

Forests ◽

10.3390/f12080968 ◽

2021 ◽

Vol 12 (8) ◽

pp. 968

Author(s):

Dong Xing ◽

Xinzhou Wang ◽

Siqun Wang

Keyword(s):

Mechanical Properties ◽

Creep Behavior ◽

Cell Walls ◽

Treated Wood ◽

Crosslinking Reaction ◽

Depth Sensing ◽

Temperature Dependent ◽

Heat Treated ◽

Static Mechanical ◽

Static Mechanical Properties

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.

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Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.576.314 ◽

2012 ◽

Vol 576 ◽

pp. 314-317

Author(s):

Sinin Hamdan ◽

M. Saiful Islam

Keyword(s):

Mechanical Properties ◽

Diazonium Salt ◽

Treated Wood ◽

Coupling Reaction ◽

Physical And Mechanical Properties ◽

Modulus Of Rupture ◽

Ft Ir ◽

Ir Analysis ◽

D Values ◽

Benzene Diazonium

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

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The Effects of Heat Treatment on the Chemical Alterations of Oak Wood

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.688.44 ◽

2016 ◽

Vol 688 ◽

pp. 44-49 ◽

Cited By ~ 1

Author(s):

Iveta Čabalová ◽

František Kačík ◽

Tereza Tribulová

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

High Performance Liquid Chromatography ◽

Renewable Energy ◽

Liquid Chromatography ◽

Thermal Treatment ◽

High Performance ◽

Treated Wood ◽

National Renewable Energy Laboratory ◽

Oak Wood

Samples prepared from oak (Quercusrobur L.) wood were exposed to heat treatment at temperatures of 160, 180, 200 and 220 oC for 3, 6, 9 and 12 hours. In both untreated and thermally treated wood there were determined extractives and lignin by National Renewable Energy Laboratory (NREL) procedures, cellulose by Seifert's method, holocellulose according to Wise, hemicelluloses as difference between holocellulose and cellulose. Monosaccharides were determined by high performance liquid chromatography (NREL).The results show that hemicelluloses are less stable at thermal treatment than cellulose. The amounts of lignin and extractives rose by increasing both temperature and time of the treatment while the amounts of hemicelluloses decreased. Thermal treatment also resulted in significant decreases of the yields of non-glucosic saccharides. Degradation of carbohydrates can cause the deterioration of mechanical properties of wood.

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Laccase-catalyzed functionalization with 4-hydroxy-3-methoxybenzylurea significantly improves internal bond of particle boards

Holzforschung ◽

10.1515/hf.2008.045 ◽

2008 ◽

Vol 62 (2) ◽

pp. 223-229 ◽

Cited By ~ 25

Author(s):

Karin Fackler ◽

Thomas Kuncinger ◽

Thomas Ters ◽

Ewald Srebotnik

Keyword(s):

Internal Bond ◽

Treatment Time ◽

Urea Formaldehyde ◽

Treated Wood ◽

Untreated Wood ◽

Strength Properties ◽

Positive Interactions ◽

Formaldehyde Resin ◽

Significant Difference ◽

Wood Particles

Abstract Enzymatic functionalization is an attractive tool to provide a reactive interface for further processing of lignocellulosic materials, such as wood particles and fibers. Here, spruce wood particles have been functionalized by fungal laccase combined with 4-hydroxy-3-methoxy-benzylamine (HMBA) or 4-hydroxy-3-methoxybenzylurea (HMBU). The expectation was crosslinking with resins in subsequent glueing processes, which should improve strength properties of particle boards. Essential process parameters, such as liquid to solid mass ratio and treatment time, were optimized on a laboratory scale resulting in HMBA and HMBU binding yields of 90% and above as determined by radiochemical mass balance analysis. We employed a multifactorial experimental design for board production from treated wood particles and urea/formaldehyde resin. Mechanical testing and multivariate data analysis revealed, for the first time, an increase of internal bond (IB) as a result of functionalization with HMBU. HMBA was not successful. Variance analysis of relevant parameters and their interactions demonstrated a highly significant difference (P>99.99%) between boards treated with laccase/HMBU versus untreated wood particles. Due to positive interactions, functionalization was most effective at high bulk density (750 kg m-3) and high resin content (10%) resulting in a calculated IB improvement of 0.12 N m-2 (21%).

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In Polymerization of Environment Friendly Melamine-Urea-Glyoxal Resin in Rubber Wood for Improved Physical and Mechanical Properties

International Journal of Polymer Science ◽

10.1155/2021/8510571 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Lijuan Ping ◽

Yubo Chai ◽

Fangwen Zhang ◽

Bailing Sun ◽

Junliang Liu

Keyword(s):

Mechanical Properties ◽

Wood Sample ◽

Treated Wood ◽

Physical And Mechanical Properties ◽

Weight Percent Gain ◽

Wood Products ◽

Environment Friendly ◽

Promising Alternative ◽

Rubber Wood ◽

Structural Applications

In the study, we report that a safe and simple way for upgrading inferior rubber wood through the combined modification of environment-friendly MUG resin was synthesized from glyoxal, melamine, urea, and other additives. MUG-treated wood samples were prepared with six different MUG resin concentrations (5, 15, 25, 35, 45, and 55 wt %) into the wood matrix and then heated and polymerized to form a solid and hydrophobic MUG resin in the wood scaffold, and the physico-mechanical properties were evaluated. As the MUG resin concentration increased, the weight percent gain and density increased, water uptake and leachability decreased, and the antiswelling efficiency increased at first and then decreased. MUG-treated wood sample can be prepared when the MUG resin concentration was set as 25%, and the physical properties of treated wood was optimum. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy analysis showed that the MUG resin is widely distributed in the cell lumens and cell walls. With enhanced physico-mechanical properties, MUG-treated wood sample can be well used as a promising alternative to existing engineered wood products for structural applications.

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Physical and Mechanical Properties of Ammonia-Treated Black Locust Wood

Polymers ◽

10.3390/polym12020377 ◽

2020 ◽

Vol 12 (2) ◽

pp. 377 ◽

Cited By ~ 5

Author(s):

Mariana Domnica Stanciu ◽

Daniela Sova ◽

Adriana Savin ◽

Nicolae Ilias ◽

Galina A. Gorbacheva

Keyword(s):

Mechanical Properties ◽

Black Locust ◽

Loss Modulus ◽

Colour Change ◽

Treated Wood ◽

Physical And Mechanical Properties ◽

Mechanical Analysis ◽

Modulus Of Rupture ◽

Elastic Behaviour ◽

Control Samples

Because of the uneven colour of black locust wood, different technologies are used to change the colour, the bestknown being chemical and thermal treatments. Some of them affect the mechanical properties of wood, such as elasticity modulus, strength, durability. This study aims to compare the physical and mechanical properties of black locust wood control samples and treated wood samples with ammonia hydroxide, in terms of density profile, colour values (CIE L*, a*, b*), mechanical properties of samples subjected to static bending, viscous-elastic properties (storage modulus (E’), loss modulus (E”) and damping (tanδ)). Two types of ammonia-fuming treatment were applied on samples: first treatment T1-5% concentration of ammonia hydroxide for 30 days; second treatment T2-10% concentration for 60 days. The results highlighted the following aspects: the overall colour change in the case of the second treatment is 27% in comparison with 7% recorded for the control samples; the lightness and yellowness values are the most affected by the second ammonia treatment of black locust wood. The density increased with almost 20% due to ammonium fuming (10% concentration/60 days); in case of static bending, the elastic modulus (MOE) tends to decrease with increasing the exposure time to ammonium, but the modulus of rupture (MOR) increases with almost 17% and the breaking force increases too, with almost 41%. In the case of dynamic mechanical analysis, the temperature leads to different viscous-elastic behaviour of each type of samples.

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