Black Poplar Wood Research Articles

Enhancing Surface Characteristics and Combustion Behavior of Black Poplar Wood through Varied Impregnation Techniques

The objective of this work was to improve the thermal stability, flame resistance, and surface properties of black poplar (Populus nigra L.) wood via different impregnation methods. The impregnation methods were employed through two distinct modalities: vacuum impregnation and immersion impregnation. Here, poplar wood was impregnated with calcium oxide solutions (1%, 3% and 5%). Fourier-transform infrared spectroscopic analysis revealed a shift in the typical peaks of cellulose, hemicellulose, and lignin depending on the impregnation method and solution ratio. Thermogravimetric analysis and the limiting oxygen index indicated that the samples impregnated with lime solutions exhibited higher thermal stability than the unimpregnated wood. Both impregnation methods caused a decrease in water absorption and thickness swelling of the sample groups. Using a scanning electron microscope, the effect of the impregnation process on the structure of the wood was examined. In terms of surface properties, it was determined that the surface roughness value increased. On the contrary, it was observed that the contact angle value also increased. A significant difference emerged between the applied methods. In conclusion, the applied lime minerals are suitable substances to increase the flame resistance and thermal stability of black poplar wood.

Use of Spinning Roller in Cylindrical Densification; Spring back in Black Poplar, Larch and Cedar of Lebanon after Densification

Wood materials have been the solution to many needs throughout history due to their unique positive properties. By improving the properties of wood materials, their areas of use can be expanded and ensured that they are preferred. The densification process is one of the studies carried out to improve wood material properties. With densification, the physical and mechanical properties of the wood material are improved. There are many different methods used for densifying wood materials. While the densification process brings many positive properties to the wood material, an undesirable situation such as spring-back after the process is the negative side of the densification process. In this study, black poplar (Populus nigra L.), larch (Pinus nigra Arnold) and cedar of Lebanon (Cedrus libani A.Rich.) trees were shaped into cylinders on a lathe. After that, densification processes were carried out on the lathe machine using the spinning roller designed and manufactured for this purpose. Densification processes were carried out at 0.081, 0.121, and 0.202 mm/rev feed, at 200 and 400 rev/min, and 0.5 and 1 mm densification depths. The spring-back rates after densification in three different types of cylindrical wood materials were investigated. Theoretical and experimental spring-back amounts of test specimens whose surfaces were densified under different densification conditions were interpreted. When evaluated in general, the highest densification rate was obtained in black poplar wood species, 0.081 mm/rotate feed, 200 rpm spindle speed and 1 mm depth of densification. The lowest spring-back ratio was obtained in larch tree species, 0.121 mm/rotate feed, 400 rpm spindle speed and 1 mm depth of densification. The highest densification percentage was obtained in black poplar tree species, and the lowest in larch tree species. The lowest percentage of spring-back was obtained in the larch tree species and the highest in the black poplar tree species.

Production and characterization of activated carbon from Black Poplar (Populus Nigra) wood waste with different chemical activation methods

In this study, the producibility of activated carbon from wood waste by using the chemical activation method was investigated and the produced activated carbon was compared with commercial activated carbon. Activated carbon was produced from black poplar wood waste using zinc chloride and phosphoric acid. The density values of the produced activated carbons were determined by the picometer method. Field Emission Scanning Electron Microscopy (FESEM) was used to analyze the microstructure and perform the elemental mapping. To determine the chemical content of activated carbon, it was also characterized by Fourier-transform infrared spectroscopy (FTIR) and energy dispersion spectroscopy (EDS). Based on the density and FE-SEM results, it was determined that the produced activated carbon had a lower density and porous structure. In addition, EDS analysis showed that the activated carbon produced from black poplar wood waste was purer than commercial activated carbon.

Influence of Thermal Modification in Nitrogen Atmosphere on the Selected Mechanical Properties of Black Poplar Wood (Populus nigra L.).

The thermal modification of wood in a nitrogen atmosphere shapes the functional properties of wood. The aim of this research was to determine the influence of different levels of temperature and the duration of thermal modification on the mechanical properties of the black poplar (Populus nigra L.). Black poplar was thermally modified in nitrogen atmosphere in the temperature range from 160 °C to 220 °C (6 levels) for 2 h to 8 h (4 levels), resulting in a total of 24 treatments. The effect of these treatments on compressive strength parallel to the grain (CS), modulus of rupture (MOR), and modulus of elasticity during bending (MOE) were analyzed. Thermal modification influenced the mechanical properties of black poplar wood. After thermal modification occurred in a nitrogen atmosphere, an increase in compressive strength was noticeable for all variants of black poplar wood modification. The highest 16% increase in CS was obtained for the modification carried out at the temperature of 160 °C and for 2 h. An increase was also found for MOE when modified under mild conditions, while a decrease occurred for variants at higher temperatures, i.e., for 200 °C and 220 °C. The study showed that for all modification variants, there was a decrease in MOR alongside the increase in modification temperature and time.

LC/MS Q-TOF Metabolomic Investigation of Amino Acids and Dipeptides in Pleurotus ostreatus Grown on Different Substrates.

The well-established correlation between diet and health arouses great interest in seeking new health-promoting functional foods that may contribute to improving health and well-being. Herein, the metabolomic investigation of Pleurotus ostreatus samples grown on two different substrates (black poplar wood logs, WS, and lignocellulosic byproducts, LcS) revealed the high potential of such a mushroom as a source of bioactive species. The liquid chromatography/mass spectrometry combined with quadrupole time-of-flight (LC/MS Q-TOF) analysis allowed the identification of essential and nonessential amino acids along with the outstanding presence of dipeptides. Multivariate statistical models highlighted important differences in the expression of both classes of compounds arising from the growth of P. ostreatus strains on WS and LcS. The former, in particular, was correlated to an increased expression of carnitine-based amino acid derivatives and proline-based dipeptides. This finding may represent a potential strategy to drive the expression of bioactive compounds of interest to obtain enriched mushrooms or useful functional ingredients from them.

UV kürlenmeli vernik uygulanmış karakavak odununda renk, parlaklık, salınımsal sertlik ve yüzeye yapışma direnci üzerine yapay yaşlandırmanın etkisi

Black poplar wood is used for the manufacture of furniture, paneling, and plywood. In this study, the relationship between 3 and 5 layers of UV system varnish applied to black poplar (Populus nigra L.) wood and artificial aging was investigated. In addition, before and after aging (252 and 504 hours), color parameters (∆E*, ∆L*, ∆a*, ∆b*, L*, a*, and b*), glossiness, pendulum hardness, and surface adhesion resistance (pull-off) tests were performed on varnished materials. According to the results obtained, for both varnish types, a decrease in surface adhesion resistance and L* value was determined with the increase of aging time after aging conditions with UVB-313 lamps, while increases were determined for a* and b* values. ∆E* values were found to be higher than that of the 3-layer application. In addition, it was determined that the measurements made in all directions and degrees glossiness for both varnish applications decreased with increasing aging time. It was observed that the pendulum hardness of the surfaces with 3 coats application was higher than that of the 5 coat application, while decreases were observed at the end of the 252 hours in both varnish types, while an increase was obtained at the end of the 504 hours. As a result, it is recommended to use this material in line with the usage areas according to the ambient conditions of the desired hardness resistance (space floor preference).

The effects of tree age, thickness, and depth of timber on density and mechanical properties of heat-treated black poplar wood (Populus nigra)

ThermoWood is a wood modification method that is used to improve the wood application and dimensional stability of wood. In this study, poplar wood (Populus nigra) was used in two age groups of 18- and 38-year-old trees to investigate the effect of tree age, thickness, and depth of heat-treated timbers on mechanical properties and density. In each age group, the timbers were prepared according to thickness of 40, 50, and 60 mm. The experimental samples were prepared from the surface (S) and middle (M) depth of heat-treated timbers based on age and thickness. Some properties of heat-treated and control wood such as density (oven-dry density, air-dry density, and basic density) and mechanical properties (modulus of rupture (MOR), modulus of elasticity (MOE), and impact strength) were measured. In general, density and mechanical properties of heat-treated wood were decreased compared with the control samples. Density and mechanical properties of heat-treated and control wood samples were increased from 18- to 38-year-old trees. There were no differences in density and mechanical properties after changing thickness. Surface and middle depth specimens of heat-treated timbers showed a positive effect on the impact strength but had no considerable effect on densities and other strengths of heat-treated wood timbers.

Influence of thermal modification in nitrogen atmosphere on the gloss of black poplar (Populus nigra L.)

Influence of thermal modification in nitrogen atmosphere on the gloss of black poplar (Populus nigra L.). Heat treatment of wood is a process to which improve mechanical and physical properties. During this treatment is observed changes aesthetic properties of wood among others gloss. The aim of this research was to conduct the influence of time and temperature on surface gloss of black poplar wood (Populus nigra L.). Wood was modified by heat treatment process in nitrogen atmosphere in temperaturę from 160 °C to 220 °C, and during the following time periods 2 h - 8 h. Under the influence of modification Surface of modified wood change the gloss of black poplar wood. There was correlation between temperaturę and gloss changing and longer time of treatment. In temperaturę 220 °C decrease og gloss was 45 % for radial section and 52 % for tangential section. Influence of time and temperature on modified black poplar wood was different and depend on section. Temperature of modification was in 20 % accountable for gloss change on radial section and in 38 % for gloss change on tangential section. Influence of time during the proces was much smaller then temperaturę parameters and was 3 % and 5 % respectively for radial and tangential section.

The Effect of Wood Species and Strip Width on Bending Strength and Modulus of Elasticity in End-Grain Core Blockboard

It is aimed to compare the bending strength and modulus of elasticity of end-grain (vertical strip) core blockboard, unlike the usual (lengthwise strip core) blockboard construction, with that of the traditional blockboard with the face-grain or edge-grain core construction. Oriental beech and black poplar woods are provided by taking care to avoid the grain irregularities and visible defects are used in the study. These timbers are used to obtain the core, top and bottom layers of the blockboard. PVAc mounting glue is used for bonding the layers together. According to the test data: The bending strength and modulus of elasticity of oriental beech blockboard are 39% and 26% higher respectively than that of end-grain core black poplar blockboards. If we evaluated by neglecting wood species, strip width was an effective factor in the bending strength and ineffective modulus of elasticity. In addition, the bending strength of the end-grain core oriental beech blockboard is 79 MPa and that of the end-grain core black poplar blockboard is 57 MPa, regardless of the width of the core strip. When these values are compared with the values of other engineered wood, the result is considered open to improvement and satisfactory.

Temperature, Time, and Interactions between Them in Relation to Colour Parameters of Black Poplar (Populus nigra L.) Thermally Modified in Nitrogen Atmosphere.

Thermal modification of wood in nitrogen atmosphere permits its usability value to be improved. The aim of the research was to determine the impact of technological modification parameters at different levels on the colour of black poplar (Populus nigra L.). Black poplar was thermally modified in nitrogen atmosphere at a range of temperatures from 160 °C to 220 °C, at times between 2 h and 8 h. The parameters of wood colour were measured according to the CIE L*a*b* colour space model. The changes in a* and b* had a non-linear profile. The maximum value of a* for black poplar wood was achieved after a modification at the temperature of 200 °C, while the maximum value of the b* parameter was achieved after modification at 190 °C. Colour changes in the ΔE of black poplar after modification at 160 °C and 170 °C were similar, and the dynamics of changes increased after modification at the temperature of 180 °C. The highest value of ΔE, around 40, was observed after modification at the temperature of 220 °C and time of 8 h. There were no statistically significant differences between the ΔE for radial and tangential sections. Statistical analysis showed that modification temperature was responsible for the variability of the L* value in 90%, and in ca. 70% for the changes in parameters a* and b*. The influence of the modification time on the colour parameters was minor—below 4%. The influence of the interaction between modification temperature and time on the colour parameters was below 10%. As a consequence, in the case of ΔE of black poplar wood, the influence of temperature was at a level of ca. 80%. On the other hand, the influence of time and the interaction between temperature and time of modification was low—below 3%.

Thermo-modified native black poplar (Populus nigra L.) wood as an insulation material

Extensive research projects have been carried out on thermal modification of wood material, yet thermal properties of thermally modified poplar wood have not been comprehensively investigated. Black poplar (Populus nigra L.) is a Eurasian species native to Italy which is rarely used for the production of high-performance products, though it is one of the least expensive hardwoods on the market. To explore alternative applications of poplar wood such as building facade or fire resistance materials, reliable data of thermal behaviour of thermally modified wood at high temperatures are needed. In this work, the thermal behaviour of native black poplar wood after thermal modification at different temperatures (180 °C, 200 °C and 220 °C) was analyzed. Thermal conductivity, thermal diffusivity and porosity were measured on poplar wood boards, as well as mass loss and wood color changes after heat treatment were quantified. Thermal conductivity of wood samples showed significant changes after treatment at 200 and 220 °C, but not at 180 °C. Wood porosity showed significant differences with the control when the samples were modified at a temperature of 220 °C. Increasing color differences were observed in wood samples by increasing the thermal modification temperature. Also, the mass loss of wood samples increased and equilibrium moisture content significantly dropped down after thermal modification. Our results showed that the use of thermally-modified black poplar wood could be considered as a viable alternative to chemically treated wood products for specific applications where high insulation is needed, such as saunas or windows, and for façades elements.

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

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).

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.

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

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.

A comparative study on some mechanical properties of black pine and black poplar woods

Pine and poplar wood types grow in many places in Turkey. Each tree species has different physical and mechanical properties due to its anatomical structures. In this study, some physical and mechanical properties of black pine (Pinus nigra) and black poplar (Populus nigra L.) wood were investigated, and compared with each other. According to the results of the research, moisture content, air-dried density, bending strength, modulus of elasticity, compression strength and impact bending strength of black pine wood were 9.77%, 508 kg/m3, 118.7 N/mm2, 9789 N/mm2, 57 N/mm2, 0.416 kgm/cm2, respectively. In addition, moisture content, air-dried density, bending strength, modulus of elasticity, compression strength and impact bending strength of black poplar wood were 9.81%, 396 kg/m3, 75.1 N/mm2, 5438 N/mm2, 42 N/mm2, 0.438 kgm/cm2, respectively.

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

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.

Effect of Thermo-Vibro-Mechanic® Densification Process on the Gloss and Hardness Values of Some Wood Materials

This study aimed to determine the gloss and hardness values of low-density wood materials densified using the Thermo-Vibro-Mechanic® (TVM) method after pretreatment with wood stain and wood preservative. This was carried out with a TVM density press that was designed and produced with the support of project 115O138 of the Scientific and Technological Research Council of Turkey (TUBITAK). The samples obtained from Uludağ fir (Abies bornmüelleriana Mattf.) and black poplar (Populus nigra L.) were pretreated with wood stain and wood preservative prior to the TVM densification process. The TVM densification operation was conducted at three different temperatures, three different vibration pressures, and three different vibration times. After the TVM densification process, changes in the gloss (ISO 2813 2014) and Brinell hardness values (TS 2479 1976) of the samples were determined. According to the results, the TVM densification method increased the gloss value of the Uludağ fir and black poplar wood pretreated with the wood preservative by 175% and 1390%, respectively, and increased the Brinell hardness value by 63% and 150%, respectively.

Effects of thermal modification on selected physical properties of sapwood and heartwood of black poplar (Populus nigra L.)

Black poplar (Populus nigra L.) was subjected to thermal modification in superheated steam. The modification was performed at 160 °C, 190 °C, and 220 °C for 2 h. The equilibrium moisture content of the black poplar wood was examined when it was exposed to 76% ± 2% relative humidity at a temperature of 20 °C ± 2 °C. The thermal modification of the poplar wood changed its moisture-exchange-related physical properties to a large extent. The effects of temperature on individual properties (density, mass loss, hygroscopicity, swelling, and water absorption) were diverse, and the intensity of these effects increased with increasing temperature of the thermal treatment process. In most cases, no significant differences were observed between the changes in properties of the sapwood and the heartwood.

Effect of the plant dye and mineral water treatment on the absorption, retention and density values of the black poplar (Populus nigra L.) wood

This study aimed to determine the effects of the plant dye and natural mineral water treatment on the absorption, retention and density values of the black poplar (Populus nigra L.) wood. Mineral water from the Antalya-Demre-Burguc Region, leaves of the quince (Cydonia vulgaris L.) tree, pomegranate (Pinuca granatum L.) and walnut (Juglans regia L.) fruit shells’ dye were used in the research. 10 different treatment liquids were prepared from the plant dyes and natural mineral water as single and double. The sapwood samples of black poplar tree were treated with these liquids by using immersion method. Then, the absorption, retention and density properties of wood samples were investigated. The results show that the natural mineral water and plant dye treatments had a statistically significant effect on the absorption, retention and density values of the black poplar wood. While the highest absorption value was obtained with 0.344 g/cm3 of mineral water + quince dye mixture, the lowest value was obtained with 0.260 g/cm3 of mineral water + walnut dye mixture. For retention, the highest (3.686%) and the lowest (0.491%) values was obtained with pomegranate dye and the quince dye, respectively. The highest density value (0.423 g/cm3) was obtained with mineral water + walnut dye mixture, but the lowest value (0.383 g/cm3) was obtained with Quince paint. In addition, the treatment of mineral water as a dual mixture with plant dyes increased the values of all three properties relative to treatments with single fluid.

Density and some mechanical properties of densified and heat post-treated Uludağ fir, linden and black poplar woods

The effects of thermo-mechanical densification and heat post-treatment on air-dry density, modulus of elasticity (MOE), bending strength (MOR), and compression strength parallel to the grain (CS) of Uludag fir (Abies bornmulleriana Mattf.), linden (Tiliagrandifolia Ehrh.), and black poplar (Populus nigra L.) wood samples were investigated. Samples were densified with compression ratios of 25 and 50%, and at 100 and 140 °C. Then, the heat treatment was applied to the samples at 185 and 212 °C for 2 h. According to the results of the study, density of all wood samples increased together with the increase of compression ratio. Regarding compression temperature, the highest density increase was obtained at 100 °C. Mechanical strength (MOE, MOR, and CS) in densified samples increased depending on compression ratio and increase of density. The highest strength increase was in black poplar samples and the lowest was in linden samples. After heat post-treatment, mechanical strength of samples decreased depending on increase in treatment temperature. However, strength values (MOR except) of samples which are 50% compressed and heat-treated were found higher than control samples.