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

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.

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

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.

scholarly journals Chemical composition as factor affecting the mechanical properties of thermally modified black poplar (Populus nigra L.)

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3915-3929
Author(s):  
Paweł Kozakiewicz ◽  
Michał Drożdżek ◽  
Agnieszka Laskowska ◽  
Marek Grześkiewicz ◽  
Olga Bytner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermal Processing ◽  
Wood Properties ◽  
Populus Nigra ◽  
Modulus Of Rupture ◽  
Wood Moisture ◽  
Black Poplar ◽  
Thermally Modified Wood ◽  
Modified Wood

Black poplar (Populus nigra L.) was thermally modified in superheated steam at 160 °C, 190 °C, and 220 °C for 2 h. The research identified correlations between the chemical composition and selected mechanical properties of thermally modified wood. The higher treatment temperatures significantly lowered the modulus of rupture (MOR) and the Brinell hardness (BH). These correlations were particularly apparent at higher temperatures (190 °C and 220 °C) when thermally modified wood experienced stronger hemicelluloses degradation, which was indicated by an increase in the content of non-structural substances. The wood properties including compressive strength parallel to the grain (CS), modulus of elasticity during bending (MOE), and compressing (MCS) were affected less by the chemical changes caused by the thermal processing of wood. Moreover, the level of wood moisture content also affected these changes.

scholarly journals Association genetics of chemical wood properties in black poplar (Populus nigra)

2012 ◽  
Vol 197 (1) ◽  
pp. 162-176 ◽  
Author(s):  
Fernando P. Guerra ◽  
Jill L. Wegrzyn ◽  
Robert Sykes ◽  
Mark F. Davis ◽  
Brian J. Stanton ◽  
...  
Keyword(s):  
Wood Properties ◽  
Populus Nigra ◽  
Association Genetics ◽  
Black Poplar

The study of the impact of in situ polymerisation with styrene or acrylates on water absorbability and swelling of thermomechanically densified poplar wood

2019 ◽  
Vol 108 ◽  
pp. 140-147
Author(s):  
ANDRZEJ RADOMSKI ◽  
MARTA GNACIŃSKA
Keyword(s):  
Nitrogen Atmosphere ◽  
Densified Wood ◽  
Poplar Wood ◽  
Dominant Effect ◽  
Thermally Induced ◽  
Volume Swelling ◽  
Water Absorbability ◽  
The Impact ◽  
Thermally Treated

The study of the impact of in situ polymerisation with styrene or acrylates on water absorbability and swelling of thermomechanically densified poplar wood. Black poplar samples, which were previously subjected to thermomechanical densification, were tested for an improvement on the field of water resistance. Series of samples were additionally thermally treated in a nitrogen atmosphere, and then series of densified only or densified and thermally treated samples were treated with monomer mixtures, containing styrene or acrylates, and co-monomers reactive toward cell wall of wood, followed by thermally induced radical polymerisation. All samples were tested by prolonged soaking in water, while volume swelling and absorbability were determined. Densified wood proved to be suitable for modification by in situ polymerisation. Thermally treated densified wood was found to be significantly more compatible with polymers used, as a decrease in its swelling was observed as dominant effect, while absorbability changes were less clear.

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

Materials ◽  
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).

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

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1581-1599
Author(s):  
Mehmet Budakçı ◽  
Süleyman Şenol ◽  
Mustafa Korkmaz
Keyword(s):  
Compression Ratio ◽  
Tangential Direction ◽  
Populus Nigra ◽  
Low Density ◽  
Poplar Wood ◽  
Application Time ◽  
Black Poplar ◽  
Different Temperatures ◽  
Tangential Directions ◽  
Control Samples

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.

Study on Properties of Modified Poplar Wood

2014 ◽  
Vol 926-930 ◽  
pp. 242-245
Author(s):  
Yong Wang ◽  
Ze Jun Chen ◽  
La Yun Deng ◽  
You Hua Fan
Keyword(s):  
Mechanical Properties ◽  
Comparative Study ◽  
Water Absorption ◽  
Dimensional Stability ◽  
Physical And Mechanical Properties ◽  
Dry Density ◽  
Poplar Wood ◽  
Absorption Ratio ◽  
Different Levels ◽  
Modified Wood

The paper based on a comparative study between poplar wood and modified poplar wood, concerning dimensional stability, physical and mechanical properties. The result showed that air-dry density and ASE value of modified wood samples were increasing in different levels with change of the modifier concentration, compared with untreated poplar wood. The air-dry density of modified wood reached 0.41 g/cm3 with increase of 5.3% compared to poplar wood. ASE reached 47.8% and the water-absorption ratio decreased by 38% at most when the modifier concentration was 30 wt.%. Moreover, the MOE and MOR of modified poplar wood increased up to 27.4% and 13% respectively when the modifier concentration was 25 wt.%. The SEM spectrum showed some wood rays and the gaps between staggered fibers were filled by modifier.

Enhancing the mechanical and water resistance performances of bamboo particle reinforced polypropylene composite through cell separation

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dan Ren ◽  
Xuexia Zhang ◽  
Zixuan Yu ◽  
Hankun Wang ◽  
Yan Yu
Keyword(s):  
Water Absorption ◽  
Cell Separation ◽  
Water Resistance ◽  
Dynamic Mechanical Properties ◽  
Simple Method ◽  
Interface Modification ◽  
Wood Particles ◽  
Bamboo Fibers ◽  
Pp Composites ◽  
Mechanical Performances

AbstractIt is frequently observed that bamboo particle composites (BPCs) do not show higher mechanical performances than the corresponding wood particles composites (WPCs), although bulk bamboo is much stronger than wood in mechanical performances. Herein this phenomenon was demonstrated from the cell compositions in the applied bamboo particles. To address that, a simple method to physically separate bamboo fibers (BFs) and bamboo parenchyma cells (BPs) from a bamboo particle mixture was developed. Polypropylene (PP) composites with pure BFs, BPs, a mixture of BFs and BPs (BFs + BPs), wood particles (WPs) as fillers were prepared. The flexural and dynamic mechanical properties, water absorption, and thermal properties were determined. The BF/PP composites showed the best mechanical performances (MOR at 35 MPa, MOE at 2.4 GPa), followed by WP/PP, (BF + BP)/PP, and BP/PP. They also exhibited the lowest water absorption and thickness swelling. Little difference was found for the thermal decomposition properties. However, a lower activation energy of BF/PP compared with BP/PP implied an uneven dispersion of BFs and weaker interfacial interaction between BF and PP. The results suggest that the mechanical performances and water resistance of bamboo particle/polymer composites can be significantly improved through cell separation. However, interface modification should be applied if higher performances of BF/PP composites are required.

scholarly journals Water Resistance and Creep Behavior of Heat-Treated Moso Bamboo Determined by the Stepped Isostress Method

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Creep Behavior ◽  
Heat Treatment Temperature ◽  
Water Resistance ◽  
Absorption Efficiency ◽  
Treatment Temperature ◽  
Moso Bamboo ◽  
Phyllostachys Pubescens ◽  
Heat Treated

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.

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