Effects of Thermo-Vibro-Mechanic® densification on the density and swelling of pre-treated Uludağ fir and black poplar wood

The radial and tangential swelling as well as the fully dried density of low-density wood materials densified via the Thermo-Vibro-Mechanic® method were evaluated in response to applying wood stain and preservative. The samples obtained from Uludağ fir (Abies bornmüelleriana Mattf.) and black poplar (Populus nigra L.) in the radial and tangential direction were pre-treated with wood stain and preservative before undergoing Thermo-Vibro-Mechanic® densification. Thermo-Vibro-Mechanic® densification was performed at three different temperatures (100 °C ± 3 °C, 120 °C ± 3 °C, and 140 °C ± 3 °C), three different vibration pressures (0.60 MPa, 1.00 MPa, and 1.40 MPa), and three different vibration times (20 s, 60 s, and 100 s). Afterwards, changes in the fully dried density and swelling amounts in the radial and tangential directions of the samples were determined. The fully dried density increased by 15.4% to 38% and the radial and tangential swelling amounts increased by 73.2% to 242.6%, when the densified samples were compared to the control samples. In general, the fully dried density and swelling values increased depending on the Thermo-Vibro-Mechanic® densification parameters; higher values were found as the compression ratio and total application time increased.

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Evaluation of the Dimensional Stability of Black Poplar Wood Modified Thermally in Nitrogen Atmosphere

Materials ◽

10.3390/ma14061491 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1491

Author(s):

Olga Bytner ◽

Agnieszka Laskowska ◽

Michał Drożdżek ◽

Paweł Kozakiewicz ◽

Janusz Zawadzki

Keyword(s):

Dimensional Stability ◽

Nitrogen Atmosphere ◽

Thermal Modification ◽

Poplar Wood ◽

Dimensional Changes ◽

Processing Times ◽

Modification Process ◽

Black Poplar ◽

Tangential Directions ◽

Modified Wood

Black poplar (Populus nigra L.) was thermally modified in nitrogen atmosphere. The effects of the modification process on poplar wood were evaluated for temperatures: 160 °C, 190 °C, and 220 °C applied for 2 h; and 160 °C and 190 °C for 6 h. The percentual impact of temperature and time of modification on the properties of modified wood was analysed. The study permitted the identification correlations between the chemical composition and selected physical properties of thermally modified poplar wood. The dimensional stability of poplar wood was improved after thermal modification in nitrogen. The higher the temperature of modification, the lower the equilibrium moisture content (EMC) of black poplar. At the temperature of 220 °C, EMC was two times lower than the EMC of non-modified black poplar. It is also possible to reduce the dimensional changes of wood two-fold (at the modification temperature of 220 °C), both in radial and tangential directions, independently of the acclimatization conditions (from 34% to 98% relative humidity, RH). Similar correlations have been found for wood that has been soaked in water. Higher modification temperatures and longer processing times contributed to a lower swelling anisotropy (SA).

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The study of selected properties of black poplar wood (Populus nigra L.) subjected to furfurylation and polymerization in lumen

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0014.6966 ◽

2020 ◽

Vol 112 ◽

pp. 11-21

Author(s):

Tomasz Gliszczyński ◽

Andrzej Antczak

Keyword(s):

Maleic Anhydride ◽

Furfuryl Alcohol ◽

Brinell Hardness ◽

Colour Change ◽

Populus Nigra ◽

Poplar Wood ◽

Test Results ◽

Black Poplar ◽

Volume Swelling ◽

Water Absorbability

The study of selected properties of black poplar wood (Populus nigra L.) subjected to furfurylation and polymerization in lumen. The aim of this work was studying black poplar wood (Populus nigra L.) selected properties modified with furfuryl alcohol and styrene. Maleic anhydride and glicydyl methacrylate were used as cross-linking agents. For modified wood samples the index of WPG, density, hardness, water absorbability, colour change and volume swelling were tested. Each test results were compared with values for unmodified black poplar wood. During furfurylation process density of poplar wood samples increased up to 1.3 times. Addition of maleic anhydride to furfurylation process caused increase of WPG index about 5-6 % and at the same time slightly decrease of wood Brinell hardness. Water absorbability and volume swelling of furfurylated poplar wood after 10080 min (168 h) of soaking in water were reduced more than 50% relative to unmodified wood. Polymerization in lumen with using styrene caused increase of density up to 2 times, increase of Brinell hardness up to 1.5 times, while WPG index was in the range from 50.8 to 116.6%. For polymerization in lumen process, water absorbability and volume swelling after 10080 min (168 h) of soaking in water were reduced more than half as well. Furfurylation caused intensive wood darkening when polymerization in lumen changed wood colour slightly. Addition of maleic anhydride to furfuryl alcohol caused an even greater darkening of the wood. The studies proved, that chemical modification significantly improved selected properties of poplar wood.

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Swelling and water resistance of black poplar wood (Populus nigra L.) modified by polymerisation in lumen with styrene

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0014.3679 ◽

2020 ◽

Vol 110 ◽

pp. 35-40

Author(s):

Emil Żmuda ◽

Andrzej Radomski

Keyword(s):

Water Absorption ◽

Water Resistance ◽

Wood Properties ◽

Populus Nigra ◽

Poplar Wood ◽

Black Poplar ◽

Initial Stage ◽

Volume Swelling ◽

Water Absorbability ◽

Modified Wood

Swelling and water resistance of black poplar wood (Populus nigra L.) modified by polymerisation in lumen with styrene. Polymerisation in lumen of black poplar (Populus nigra L.) was performed to improve wood properties related to interaction with water. Wood samples were modified with styrene or a mixture of styrene and maleic anhydride, using benzoyl peroxide as initiator. Polymerisation was conducted in closed vessels at a temperature up to 120 °C. Volume swelling and water absorbability of modified wood samples were measured. A significant decrease in the rate of water absorption was found, especially at the initial stage of soaking, resulting in 50 % decrease in volume swelling and 85 % decrease in water absorption.

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A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽

10.3390/nano11081885 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1885

Author(s):

Xinyu Wu ◽

Feng Yang ◽

Jian Gan ◽

Zhangqian Kong ◽

Yan Wu

Keyword(s):

Stearic Acid ◽

Antibacterial Properties ◽

Alkali Resistance ◽

Poplar Wood ◽

X Ray Diffraction ◽

X Ray ◽

Different Temperatures ◽

Acid And Alkali Resistance ◽

The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

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