scholarly journals Bending Strength of Wood Treated with Propolis Extract and Silicon Compounds

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 819
Author(s):  
Magdalena Woźniak ◽  
Przemysław Mania ◽  
Edward Roszyk ◽  
Izabela Ratajczak
Keyword(s):  
Bending Strength ◽  
Creep Compliance ◽  
Treated Wood ◽  
Untreated Wood ◽  
Creep Process ◽  
Creep Tests ◽  
Silicon Compounds ◽  
Propolis Extract ◽  
Relative Creep ◽  
Control Samples

The modification of wood and its treatment with various preservatives may affect its mechanical properties, hence the knowledge of the character changes in wood caused by impregnation is of great importance. Therefore, the aim of the research was to determine the effect of impregnation, with the propolis-silane preparation (EEP-MPTMOS/TEOS) consisting of the propolis extract (EEP) and silicon compounds: 3-(trimethoxysilyl)propyl methacrylate (MPTMOS) and tetraethoxysilane (TEOS), on the bending strength of treated wood. Moreover, in the study wood treated with components of the propolis-silane formulation was used, namely 70% ethanol, the propolis extract, and silanes (MPTMOS/TEOS). In order to determine whether the impregnation of wood affects its long-term bending, creep tests were performed depending on the humidity. The impregnation of wood with the propolis extract and the propolis-silane preparation (EEP-MPTMOS/TEOS) contributed to the increase in modulus of rapture and work to maximum load values compared to the untreated wood. In dry wood condition, the wood treated with EEP and EEP-MPTMOS/TEOS was characterized by lower modulus of elasticity values than the control samples. In turn, in wet wood condition, wood treated with the propolis-silane preparation showed an increase in the MOE value. Moreover, the impregnation of wood had an influence on the wood creep process under bending loads. The treated wood was characterized by higher relative creep compliance than the untreated wood. The exception was the wood impregnated with EEP-MPTMOS/TEOS, which showed comparable relative creep compliance to the control samples. The presented results indicate that wood treated with a bio-friendly preparation based on propolis and silicon compounds can be used in various application and also in variable humidity conditions.

scholarly journals Chemical, Biological and Mechanical Characterization of Wood Treated with Propolis Extract and Silicon Compounds

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 907
Author(s):  
Magdalena Woźniak ◽  
Patrycja Kwaśniewska-Sip ◽  
Michał Krueger ◽  
Edward Roszyk ◽  
Izabela Ratajczak
Keyword(s):  
Bending Strength ◽  
Treated Wood ◽  
Untreated Wood ◽  
Brown Rot ◽  
Tetraethyl Orthosilicate ◽  
Wood Preservatives ◽  
Green Wood ◽  
Silicon Compounds ◽  
Propolis Extract ◽  
Before And After

The development of new bio-friendly alternatives for wood conservation is of great interest and necessary for environmental protection. In this paper, the preparations based on the propolis extract and silicon compounds were used as green wood preservatives. The wood was treated with 15% propolis extract (EEP) and two propolis-silane preparations, namely, EEP-VTMOS/TEOS (EEP with vinyltrimethoxysilane and tetraethyl orthosilicate) and EEP-MPTMOS/TEOS (EEP with 3-(trimethoxysilyl) propyl methacrylate and tetraethyl orthosilicate). The aim of the research was to determine the properties of treated wood, which was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy (AAS), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Moreover, the resistance against brown-rot fungus Coniophora puteana and the mechanical properties of treated wood were also determined. The analysis of phenolic compounds concentration in treated wood indicated that phenols were in greater extent leached from wood treated with the propolis extract than from wood impregnated with the propolis-silane preparations. The presence of silicon in treated wood both before and after leaching was confirmed by CP MAS NMR measurements. In turn, AAS and XRF analyses indicated that the degree of Si leaching from wood impregnated with EEP-VTMOS/TEOS was approximately two times lower than from EEP-MPTMOS/TEOS treated wood. The results of chemical analyses confirmed that the constituents of the propolis-silane preparations formed permanent bonds with wood. In turn, the results of the antifungal efficacy against C. puteana showed that the propolis extract and the propolis-silane preparations limited the fungus activity, even the wood was subjected to leaching procedure. The treated wood showed an increase in bending strength and a decrease in the modulus of elasticity compared to untreated wood. The obtained results indicate that the propolis-silane preparations can be promising green wood preservatives, harmless for the natural environment.

Effect of accelerated aging on the color changes of wood treated with eco-friendly formulations based on propolis and silicon compounds

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3667-3677
Author(s):  
Barbara Lis ◽  
Magdalena Woźniak ◽  
Tomasz Krystofiak ◽  
Izabela Ratajczak
Keyword(s):  
Color Change ◽  
Treated Wood ◽  
Accelerated Aging ◽  
Ethanolic Extract ◽  
Tetraethyl Orthosilicate ◽  
Water Leaching ◽  
Ir Radiation ◽  
Silicon Compounds ◽  
Propolis Extract ◽  
Color Changes

The aim of this work was to determine the effect of propolis extract and propolis-silane formulations on the color of wood. Additionally, the aim was to assess the influence of accelerated aging (water leaching and UV+IR radiation) on the color change of the treated wood. Scots pine wood was treated with the ethanolic extract of propolis and two propolis-silane formulations. The first formulation contained the propolis extract and silanes, 3-(trimethoxysilyl)propyl methacrylate, and tetraethyl orthosilicate. The second formulation comprised propolis extract, vinyltrimethoxysilane, and tetraethyl orthosilicate. The wood impregnation with the propolis extract and propolis-silane formulations had a significant effect (p ≤ 0.05) on the color change. This effect involved decreasing the L* parameter and the displacement of a* and b* coordinates in the red and yellow direction, respectively. The propolis extract and the propolis-silane formulations were characterized by low durability relative to the effect of light. Nevertheless, the examined formulations based on natural substances (propolis) and low toxicity chemical compounds (silanes) may be used to impregnate wood elements for indoor applications.

scholarly journals Air permeability and sound absorption coefficient changes from ultrasonic treatment in a cross section of Malas (Homalium foetidum)

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Chun-Won Kang ◽  
Eun-Suk Jang ◽  
Nam-Ho Lee ◽  
Sang-Sik Jang ◽  
Min Lee
Keyword(s):  
Absorption Coefficient ◽  
Ultrasonic Treatment ◽  
Sound Absorption ◽  
Gas Permeability ◽  
Treated Wood ◽  
Untreated Wood ◽  
Sound Absorption Coefficient ◽  
Permeability Constant ◽  
Average Value ◽  
Permeability Increase

AbstractWe investigated the effect of ultrasonic treatment on Malas (Homalium foetidum) gas permeability and sound absorption coefficient using the transfer function method. Results showed a longitudinal average Darcy permeability constant of 2.02 (standard deviation SD 0.72) for untreated wood and 6.15 (SD 3.07) for ultrasound-treated wood, a permeability increase of 3.04 times. We also determined the average sound absorption coefficients in the range of 50 to 6.4 kHz and NRC (noise reduction coefficient: average value of sound absorption coefficient value at 250, 500, 1000, and 2000 Hz) of untreated Malas. Those values were 0.23 (SD 0.02) and 0.13 (SD 0.01), respectively, while those of ultrasonic-treated Malas were 0.28 (SD 0.02) and 0.14 (SD 0.02), a 19.74% increase in average sound absorption coefficient.

Growth behavior of wood-destroying fungi in chemically modified wood: wood degradation and translocation of nitrogen compounds

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Maja Bleckmann ◽  
Sarah Strohbusch ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
...  
Keyword(s):  
Protective Action ◽  
Treated Wood ◽  
Untreated Wood ◽  
Brown Rot ◽  
Decay Resistance ◽  
White Rot ◽  
Decay Fungi ◽  
Chemically Modified ◽  
Decay Tests ◽  
Modified Wood

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.

Effect of Cure State on Stress Relaxation in 3501-6 Epoxy Resin

1997 ◽  
Vol 119 (3) ◽  
pp. 262-265 ◽  
Author(s):  
S. R. White ◽  
A. B. Hartman
Keyword(s):  
Stress Relaxation ◽  
Epoxy Resin ◽  
Creep Compliance ◽  
Numerical Technique ◽  
Matrix Material ◽  
Relaxation Modulus ◽  
Master Curves ◽  
Creep Tests ◽  
Three Point Bending ◽  
Direct Inversion

Little experimental work has been done to characterize how the viscoelastic properties of composite material matrix resins develop during cure. In this paper, the results of a series of creep tests carried out on 3501–6 epoxy resin, a common epoxy matrix material for graphite/epoxy composites, at several different cure states is reported. Beam specimens were isothermally cured at increasing cure temperatures to obtain a range of degrees of cure from 0.66 to 0.99. These specimens were then tested in three-point bending to obtain creep compliance over a wide temperature range. The master curves and shift functions for each degree of cure case were obtained by time-temperature superposition. A numerical technique and direct inversion were used to calculate the stress relaxation modulus master curves from the creep compliance master curves. Direct inversion was shown to be adequate for fully cured specimens, however it underpredicts the relaxation modulus and the transition for partially cured specimens. Correlations with experimental stress relaxation data from Kim and White (1996) showed that reasonably accurate results can be obtained by creep testing followed by numerical conversion using the Hopkins-Hamming method.

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

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 223-229 ◽  
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%).

scholarly journals Application of Waterborne Acrylic and Solvent-Borne Polyester Coatings on Plasma-Treated Fir (Abies alba M.) Wood

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 370
Author(s):  
Hadi Gholamiyan ◽  
Behnam Gholampoor ◽  
Reza Hosseinpourpia
Keyword(s):  
Plasma Treatment ◽  
Treated Wood ◽  
Abies Alba ◽  
Untreated Wood ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Accelerated Weathering ◽  
Water Contact ◽  
Before And After ◽  
Carbon Dioxide Co2

This research investigates the effect of plasma treatment with air, nitrogen (N2), and carbon dioxide (CO2) gases on the performance of waterborne (acrylic) and solvent-borne (polyester) coated fir (Abies alba M.) wood samples. The properties of the plasma-coated samples were analyzed before and after exposure to accelerated weathering and compared with those of untreated and solely treated ones. According to pull-off testing, the coating adhesion of the wood samples was considerably improved by plasma treatment, and obvious differences were observed between different plasma gases. The effect was more pronounced after the weathering test. Similar results were obtained for the abrasion resistance of the samples. The water contact angle measurement illustrated more hydrophilic character in the solely plasma-treated wood in comparison with the untreated wood. The application of coatings, however, strongly improved its hydrophobic character. The performances of waterborne and solvent-borne coatings on plasma-treated wood were comparable, although slightly better values were obtained by the waterborne system. Our results exhibit the positive effect of plasma treatment on coating performances and the increased weather resistance of the waterborne and solvent-borne coating systems on plasma-treated wood.

scholarly journals COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD

2014 ◽  
Vol 2 ◽  
pp. 345-352 ◽  
Author(s):  
Cristina Marinela Olarescu ◽  
Mihaela Campean
Keyword(s):  
Heat Treatment ◽  
Mass Loss ◽  
Color Change ◽  
Treated Wood ◽  
Untreated Wood ◽  
Cost Effective ◽  
Assessment Procedure ◽  
Mathematical Correlation ◽  
Heat Treated ◽  
Two Parameters

Heat treatment is renowned as the most environmentally friendly process of dimensional stabilization that can be applied to wood, in order to make it suitable for outdoor uses. It also darkens wood color and improves wood durability. The intensity of heat treatment can be appreciated by means of two parameters: the color change occured in wood due to the high temperature, and the mass loss, which is a measure of the degree of thermal degradation. In order to find a mathematical correlation between these two parameters, an experimental study was conducted with four European wood species, which were heat-treated at 180°C and 200ºC, for 1-3 hours, under atmosheric pressure.The paper presents the results concerning the color changes and mass losses recorded for the heat-treated wood samples compared to untreated wood.  For all four species, the dependency between the color change and the mass loss was found to be best described by a logarithmic regression equation with R2 of 0.93 to 0.99 for the soft species (spruce, pine and lime), and R2 of 0.77 for beech. The results of this study envisage to simplify the assessment procedure of the heat treatment efficiency, by only measuring the color – a feature that is both convenient and cost-effective. 

scholarly journals QUANTITATIVE PHYTOCHEMICAL SCREENING AND TERMICIDAL ACTIVITIES OF EUPHORBIA TIRUCALLI L. EXTRACTS ON DANIELLIA OLIVERI (ROLFE) HUTCH. AND DALZIEL AND FICUS CAPENSIS THUNB. WOODS

2020 ◽  
Vol 4 (3) ◽  
pp. 99-106
Author(s):  
David Oriabure Ekhuemelo ◽  
Francis Sarwuan Agbidye ◽  
Blessing Igoche
Keyword(s):  
Weight Loss ◽  
Methanol Extract ◽  
Treated Wood ◽  
Untreated Wood ◽  
Plant Parts ◽  
Euphorbia Tirucalli ◽  
Randomized Design ◽  
Percentage Weight ◽  
Percentage Absorption ◽  
Daniellia Oliveri

This study investigated effect of Euphorbia tirucalli extracts on Daniellia oliveri and Ficus capensis woods. Wood samples were purchased and processed into 10 cm x 2 cm x 2 cm dimensions, while plant parts collected were oven dried before extraction. E. tirucalli  was screened for phytochemicals. Concentrations of 0.5%, 1% and 2% extracts were prepared by serial dilution. Soligum, methanol and untreated wood samples were used as control. Treated wood samples were laid within 6 x 12 metres field at 1 x 3 metres spacing in a Completely Randomized Design (CRD) in a termitarium and data were taken within 8 weeks. Phytochemical results indicated the presence of alkaloids, phenols, tannins, cardiac glycosides, flavonoids and saponins. Percentage absorption of extracts ranged from 47 - 86 % and 94.00 - 50.67 % in D. oliveri and F. capensis, respectively. Percentage retention of extracts ranged from 10.84 - 2.14 kg/m3 and 11.62 - 7.01 kg/m3 in D. oliveri and F. capensis. Soligum treated wood samples were not attacked throughout the period of study. D. oliveri and F. capensis woods treated with 0.5% E. tirucalli methanol extract were not attached on till the 6th and 8th week respectively. The least percentage weight loss of 5.49 % and 28.32 % were recorded for D. oliveri and F. capensis woods treated with soligum, while, 27.5 5 % and 52.50 % weight loss were recorded for F. capensis and D. oliveri woods treated with 0.5% methanol extract. It was concluded that the use o

CORRELATION DEPENDENCES OF THE BENDING STRENGTH OF POLYMER COMPOSITE MATERIALS MODIFIED IN A MICROWAVE ELECTROMAGNETIC FIELD ON THE MOISTURE CONTENT DURING EXPOSURE IN FULL-SCALE CONDITIONS

2021 ◽  
pp. 3-9
Author(s):  
I. V. Zlobina ◽  
I. S. Katsuba
Keyword(s):  
Electromagnetic Field ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Moisture Content ◽  
Bending Strength ◽  
Climatic Factors ◽  
Experimental Studies ◽  
Three Point Bending ◽  
Treated Carbon ◽  
Control Samples

Experimental studies of the influence of external climatic factors, taking into account exposure, on the change in the bending strength of control and microwave – treated carbon and fiberglass samples in the cured state were performed. An increase in the limit stresses of three – point bending of experimental carbon fiber samples compared to the control ones was found by 7…12 %, and fiberglassby 4…7 %. It is shown that with an increase in exposure to 14 months, the strength of control samples of carbon and fiberglass decreases by an average of 10 %. At the same time, the strength of the prototypes is reduced only by 4.4 %. With an increase in the moisture content of both control and experimental samples, a decrease in their strength is observed. In this case, the linear correlation is average (from– 0.44 to – 0.615). It is established that for experimental samples, the influence of the amount of absorbed moisture on the strength is manifested to a much lesser extent. For carbon fiber, the reduction is 16.6 %, for fiberglass – 12 %.

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