Digital image correlation (DIC) was used to examine the strain distribution of heat-treated beech... more Digital image correlation (DIC) was used to examine the strain distribution of heat-treated beech and Uludag fir woods in mechanical testing. It also evaluated the effects of the heat treatment process on the properties of the wood samples. The physical (mass/density loss, dimensional stability, color change, and surface roughness), mechanical (flexure test and compressive strength), morphological, thermal, and structural properties of the heat-treated wood were examined. It was determined that the heat treatment parameters can be optimized using the DIC method. The test results showed that although heat treatment can provide improved physical and thermal properties, it caused micro-crack formations and collapses in the wood cells. As a consequence, the mechanical properties of the heat-treated wood materials decreased with the heat treatment process. There were slight differences in the curves of the samples according to Fourier infrared and X-ray diffraction analyses. Morphological characterization showed that the heat treatment triggered large cracks in the cell wall and lumens and the morphological structure of heat-treated wood was affected at large percentages.
The aim of this paper was to investigate the effects of wood flour on the mechanical, morphologic... more The aim of this paper was to investigate the effects of wood flour on the mechanical, morphological and thermal properties of poly (L-lactic acid) (PLA)-chitosan biopolymer composites produced by compression molding. The composites were characterized by a combination of mechanical properties, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The addition of chitosan to PLA matrix reduced the tensile strength from 57,1 MPa for pure PLA to 34,3 MPa for 5% chitosan and 11,5 MPa for 10% chitosan, and the flexure strength from 72,3 MPa for pure PLLA to 30,4 MPa for 5% chitosan and 24,6 MPa for 10% chitosan. The change trend in the young's modulus was found to be similar as compare with the tensile strength. However, the flexure modulus generally increased with the addition of the chitosan as comparison with pure PLA. The mechanical properties of the PLA-chitosan blends with wood flour were found to be lower than theirs of the pure PLA. According to SEM images, some holes and small voids at various diameters on the fractured section of the all composites were seen. T onset , T 10% , T 50% , T 85% of the pure PLA decreased with the addition of both chitosan and wood flour. Thermal stability of the PLA-chitosan blends was determined to be better than the PLA-chitosan composites with wood flour.
İnsanlık tarihi boyunca en yaygın hammadde ahsap olmuştur. Sanayinin gelişmesiyle tüketim artmış ... more İnsanlık tarihi boyunca en yaygın hammadde ahsap olmuştur. Sanayinin gelişmesiyle tüketim artmış ve alternatif malzemelerin gerekliliği doğmuştur. Bu gerekliliğin bir sonucu olarak, düşük kaliteli ashap malzemenin yapıştırılmasıyla lamine malzemeler elde edilmiştir. Elde edilen bu materyal birçok alanda kullanıma başlamıştır. Ahşap lamine malzemelerin iç ve dış ortam şartlarında uzun süre dayanıklı kalabilmesini sağlamak için ahşap malzeme çeşitli emprenye maddeleriyle muamele edilmektedir. Bu işlem sonrası lamine malzemenin üretilmesi süresince rutubet arttığı için ahşap malzemenin bir birlerine tutunma yetenekleri düşmektedir. Bu durumda lamine malzemelerin de yapışma önemli bir durum olmaktadır. Yapışma direncinin artmasıyla iyi malzemeler elde edilmektedir. Tam tersi durumunda ise çeşitli hatalar oluşmaktadır. Bu hataları engellemek için yapışmayı etkileyen faktörlerin bilinmesi önem arz etmektedir. Çalışmada yapışmayı etkileyen en önemli faktörler araştırılmıştır.
Düzce Üniversitesi bilim ve teknoloji dergisi, Mar 7, 2016
Termoset bir polimer olan epoksi, birçok alanda kullanımı olan bir materyaldir. Suya, aside ve al... more Termoset bir polimer olan epoksi, birçok alanda kullanımı olan bir materyaldir. Suya, aside ve alkaliye direnci çok yüksek, zamanla direnç özelliğini kaybetmez ve bu yüzden birçok materyalin ya da kompozitin hazırlanmasında kullanılabilmektedir. Özellikle yüzey kaplamalarında ve yüzey özelliklerinin iyileştirilmesinde farklı katkı maddeleriyle birlikte kullanılabilmektedir. Bu çalışmada; lamine kayın panellerin fiziksel, mekanik ve yüzey morfolojisi üzerine Mikrofibril selüloz (MFC), Nanofibril selüloz (NFC), pamuk (C) ve α-selüloz (AC) katkılı epoksi tutkalının etkileri araştırılmıştır. Lamine malzemeler 5 katmanlı olarak Doğu kayını (Fagus orientalis) odunu kullanılarak yapılmıştır. Analiz sonuçlarına göre epoksi'ye eklenen farklı katkı maddelerinin, lamine malzemelerin yoğunluk değerlerini kısmen yükselttiği belirlenmiştir. Yoğunluk değerlerine göre tam kuru rutubette NFC ilaveli lamine kompozitlerin yoğunluğu 0.70 gr/cm³, hava kurusu rutubette MFC'li kompozitlerin 0.74 gr/cm³ ve %100 rutubette ise kontrol örneklerinde 0.90 gr/cm³ olarak belirlenmiştir. Elde edilen mekanik özelliklere bakıldığında sırasıyla en yüksek eğilme direnci, MFC içeren kompozitlerde 118,5 MPa; eğilmede elastikiyet modülü ve basınç direnci ise C'li numunelerde 9385 MPa ve 66.81 MPa Olarak belirlenmiştir. Elektron mikroskobu yardımıyla yapılan yüzey analizlerinde ise katkı maddelerinin yüzeyde tutunmayı artırarak mekanik özellikleri yükselttiği belirlenmiştir.
e coating of wood and wood panel surfaces basically serves for surface protection and its surface... more e coating of wood and wood panel surfaces basically serves for surface protection and its surface can be improved at various user areas. Di erent application methods are used for the coating of MDF surface. ese are methods such as curtain coating, spraying, rolling, knife, etc. In this study, suitability of pigment coating method instead of the traditional surface coating methods used for coating MDF panels and the e ects of re retardants on surface properties of MDF coated by the best appropriate coating mixture was investigated. Calcite and clay were used as coating pigment and latex, urea formaldehyde, and melamine formaldehyde were used as adhesive. Coating/adhesive mixture obtained was applied to MDF panels with knives. Before the analysis, test samples were put to condition room and they were kept in there for 1 week. According to the results obtained, the best appropriate coating material was found as calcite. 22% concentrated melamine formaldehyde as adhesive and 0.25 mm as coating thickness was determined better than other combinations. Borax, boric acid and zinc borate as re retardant were added to calcite /melamine formaldehyde with 22% mixture. So, the e ects of re retardant on surface characterization were determined. Surface properties of coated MDF panels tested were found lower than standard requirements except for abrasion resistance.
The objective of this study is to evaluate the effect of décor paper and resin type on physical p... more The objective of this study is to evaluate the effect of décor paper and resin type on physical properties, mechanic properties, and surface quality properties of particleboards coated with décor papers impregnated by using different resin. White oak, New wenge and common maple pattern decor papers impregnated with urea formaldehyde (UF), melamine formaldehyde (MF) and urea-melamine formaldehyde (UF+MF) were used as coating materials. Particleboard surface was laminated with these coating materials by hydraulic press. As a result, specimens coated with MF-impregnated papers showed better performance than those coated with UF and UF+MF-impregnated papers. Resin type and paper pattern affected the physical, mechanical (with exception of tension strength), and surface properties (especially cigarette burn and abrasion) of coated particleboards. Physical and mechanical properties of coated particleboard were significantly improved compared to non-laminated particleboards. It was found that paper pattern affected the surface properties, such as impact, scratch, and abrasion, resistance to staining and cigarette burn. However, it did not change the cracking and steaming properties of the coated samples. After the coating process, it was determined that cigarette burn, abrasion, impact, and scratch performances were among 1 to 3 grade, lp:10-35, Fp:210-340/100-150, and 2 to 5 grade, respectively.
Polyvinyl acetate (PVAc) is a thermoplastic polymer widely used in the furniture industry. It has... more Polyvinyl acetate (PVAc) is a thermoplastic polymer widely used in the furniture industry. It has many advantages such as easy processing, cheap, biodegradable; but, resistance to water and hot medium is not enough to the application area. In this study, the effect of nano-TiO 2 and nano-SiO 2 on bonding performance and structural properties of PVAc were investigated. Bonding strength with block shear test and structural properties with thermogravimetric analysis-TGA, X-ray diffraction-XRD, and transmission electron microscopy-TEM of PVAc were determined. The obtained results showed that bonding strength with cooperating both TiO 2 and SiO 2 for 1% and 2% were improved. XRD and TEM results proved to be the homogenously interactions for 1% and 2% between nano fillers and matrix. TGA results showed that thermal stability of PVAc blends was largely improved.
In this study, we investigated the effect of fire retardants (FRs) on the combustion performance ... more In this study, we investigated the effect of fire retardants (FRs) on the combustion performance of medium-density fiber boards (MDFs) that were coated with mixtures of water, binder, calcite, and various FRs (FR coatings). We used MDF panels, calcite as the coating pigment, melamine formaldehyde as the binder, and FRs, including borax (BX), boric acid (BA), and zinc borate (ZB), to investigate the effects on the properties of the test boards. According to the results of combustion properties of coated MDFs with FR coatings, BA presented the highest stability, followed by BX and ZB, respectively. It was also found that the fire resistance of coated MDFs was better than that of uncoated MDF panels. For samples coated with FR coatings, the lowest burning temperature of 3% BA coatings was about 216 °C, and the highest burning temperature of 1% BX coatings was found as approximately 271 °C. The lowest mass losses were 35.5% for BA and 36% for BX. As a result, both surfaces of MDF panel can be coated with a mixture of calcite and FR, thereby improving the combustion properties of the MDFs. BA coatings showed to be have better thermal properties than both BX and ZB coatings.
Thermal instability is the one of the most important disadvantages of wood since it begins to dec... more Thermal instability is the one of the most important disadvantages of wood since it begins to decompose at a low temperature (˃110 °C). Many scientists, past and present, have conducted studies aimed at improving the thermal stability of wood. The aim of this study was to impregnate wood with nano-sized boron nitride (NBN) to improve its thermal stability and to investigate the changes in the properties of Scots pine (Pinus sylvestrist), Ash (Fraxinus exelsior), and Iroco (Chlorophora excelsa) woods after the impregnation. The effects of the impregnation with NBN also were investigated on the heat-treated woods. The impregnation was conducted with using full-cell method in a chamber under a pressure of 0.6 MPa for 1 h. Densities at 0% and 12% moisture content (MC), mechanical properties, color changes, thermal stability, and scanning electron microscopy (SEM/EDAX) analysis were determined. The test results showed that the impregnation of wood with NBN increased generally the flexural strength and elasticity of modulus at bending, but the NBN impregnation decreased generally the compression strength except for ACI, ATWI, IC, and ICI. It was also determined that the changes in density and color were statistically different after the impregnation. According to the SEM/EDAX results, deposits of nano-sized boron nitride were found inside the cell wall and on the pits. But the deposits were also determined in inside structure of the wood with EDAX analysis. Thermal stability in T 10% and T 50% of wood was found to improve after the impregnation with NBN. TG/DTG and DTA values for some samples were found to fluctuate due to the heterogeneous dispersion of the NBN in the wood.
Journal of Bartin Faculty of Forestry, Dec 15, 2020
In this study, the physical and mechanical properties of medium density fiber boards (MDF) produc... more In this study, the physical and mechanical properties of medium density fiber boards (MDF) produced with urea formaldehyde adhesive reinforced with nano-boron nitride (BN) and nano-titanium dioxide (TiO2) were investigated. 0.5% and 1.5% nano-filled urea formaldehyde adhesives were used in the production of test samples. The density, thickness swelling, water uptake, internal bond strength, bending strength, modulus of elasticity in bending and SEM analysis of the boards prepered were determined. According to the laboratory tests conducted, there was no significant change in the density of the boards after nano filling. Physical properties such as water intake and thickness swelling were determined to decrease with the addition of nano particles. The mechanical properties of the boards increased with the addition of both nano-BN and TiO2. According to the a results of thermogravimetric analysis, it has been determined that the thermal stability of urea formaldehyde adhesive with TiO2 is increased and maximum mass loss temperatures are higher than the addition of nano-BN. The morphological structure of the urea formaldehyde adhesive was visualized with an electron microscope, and the nanoparticle dispersions were displayed and the particles were also analyzed by EDAX analysis. As a result, it has been determined that MDFs prepared with nanoparticle adhesives have improved physical, mechanical and thermal properties. Particularly, all samples with nano particles have been achieved the standards required in their mechanical properties. As a result, it can be sad that the adding nano-particles have positive effect on the physical and mechanical properties of the panels.
Biopolymer blends of polyhydroxybutyrate and polylactic acid reinforced with cellulose nanofibril... more Biopolymer blends of polyhydroxybutyrate and polylactic acid reinforced with cellulose nanofibrils Deniz Aydemir (Conceptualization) (Methodology) (Data curation) (Formal analysis) (Writing -original draft), Douglas J. Gardner (Funding acquisition) (Project administration) (Writing -review and editing)
In this paper, the effect of cellulose nanofibrils (CNFs) loading levels on the conventional and ... more In this paper, the effect of cellulose nanofibrils (CNFs) loading levels on the conventional and dynamic mechanical, morphological, thermal and rheological properties of the polyhydroxybutyrate (PHB) biopolymers were studied. According to the results, adding CNFs from 1% to 20% generally didn’t provide any improvement in the flexural, tensile and izod impact strength attributable to void formation and pulling out and agglomeration of nanofibrils in the matrix, which was observed during morphological characterization, however adding CNFs substantially increased both flexural and tensile modulus of elasticity. Thermal analysis showed that adding CNFs generally decreased degradation at high temperatures of the biopolymer nanocomposites (BNCs) The addition of CNFs at 1, 10 and 20% increased the E' and E'' of neat PHB but the other loadings decreased them, and tan delta increased with CNF loadings of 3, 5, 10 and 20%, and finally adding CNFs didn’t change the rheological behavior of the composites.
Ahşap malzemenin (özellikle yapı sektöründe) olabildiğince homojen olması istenmektedir. Ağaçları... more Ahşap malzemenin (özellikle yapı sektöründe) olabildiğince homojen olması istenmektedir. Ağaçların büyüme dönemlerinin ilk yıllarında (yaklaşık olarak 5 ile 20 yıl arası) oluşan genç odun bu homojenliğin bozulmasına neden olabilir. Çünkü genç odun anatomik ve teknolojik özellikler bakımından olgun odundan (genç odundan sonra oluşan ve daha yüksek direnç değerlerine sahip olan kısım) daha farklı özelliklere sahiptir. Ülkemizde özellikle kereste endüstrisi olmak üzere, orman ürünleri sanayinde kullanılan ağaçların (çam türleri, karaağaç, kızılağaç, kayın vb.) genç odun dokusunun özelliklerinin belirlenmesi büyük önem taşımaktadır. Zira genç odun dokularının mekanik özellikleri olgun odundan daha düşüktür. Bu nedenle doğal genç ormanlardan ya da plantasyonlardan üretilen ağaç malzemelerde beklenmedik sonuçlar ortaya çıkarabilir. Bu çalışmada, ağaçların genç ve odun dokularının fiziksel, kimyasal ve mekanik özelliklerinin karşılaştırıldığı çalışmalar mercek altına alınarak yorumlanmıştır. Bu sayede, odun esaslı malzemelerin teknolojik özelliklerine, ağaç yaşının etkisi bilimsel olarak ortaya konmaktadır.
The aim of this study was to investigate some of the physical, mechanical, thermal and morphologi... more The aim of this study was to investigate some of the physical, mechanical, thermal and morphological properties of wood fl our and cellulose fi ber fi lled polypropylene composites. Polypropylene as a polymer matrix and wood fl our and cellulose fi bers were used as reinforcing fi llers to prepare the composites by using a single screw extruder. Physical properties such as density, mechanical properties such as fl exure strength and fl exure modulus, tensile strength and tensile modulus, and impact strength, thermal behavior with thermogravimetric analysis (TGA/DTA), and morphological characterization with scanning electron microscopy (SEM) of the composites were determined. The density of the composites was found to increase with the addition of fi llers. The mechanical properties of the composites showed that the fl exure and tensile strength for the composites with wood fl our was higher than the composites with cellulose fi bers, whereas fl exure and tensile modulus, and impact strength for the composites with cellulose fi bers was found to have higher values as compared to the composites with wood fl our. SEM pictures showed that particles and fi bers dispersed to different locations in polypropylene matrix. According to the TGA results, thermal degradation of all the composites was found to be lower compared to neat polymer.
Mehmet Akif Ersoy Üniversitesi Fen Bilimleri Enstitüsü Dergisi
Ahşabın tüm fiziksel, mekanik ve estetik özellikleri, heterojen biyolojik hücre yapısıyla oluşur.... more Ahşabın tüm fiziksel, mekanik ve estetik özellikleri, heterojen biyolojik hücre yapısıyla oluşur. Ahşap incelemelerinde, mikroskobik ve hatta ultrastrüktürel düzeyde ahşap kırılmasının doğasına ilgi artmıştır. Taramalı Elektron Mikroskobu (SEM), ahşap yapı araştırmalarını mümkün kılan en güçlü tekniklerden biri gibi görünmektedir. Çalışmada Doğu çınarı (Platanus orientalis L.) odunu kullanılmıştır. Hazırlanan numunelere çekme ve basınç direnci testleri uygulanmıştır. Mekanik testleri yapılan örneklerin deforme olan bölümlerinden kesitler alınmıştır. Bu kesitlerde Taramalı Elektron Mikroskobu incelemeleri yapılmış ve hücre görüntüleri mikrograflar kullanılarak analiz edilmiştir. Mikrograflarda, çekme direnci testleri sonucu hücre yapılarında meydana gelen parçalanarak kopma ve hücrelerin parçalanma şekilleri, basınç direnci testleri sonucu hücre duvarlarındaki çatlaklar, ayrılmalar ve kırıklar açıkça görülebilmiştir.
Digital image correlation (DIC) was used to examine the strain distribution of heat-treated beech... more Digital image correlation (DIC) was used to examine the strain distribution of heat-treated beech and Uludag fir woods in mechanical testing. It also evaluated the effects of the heat treatment process on the properties of the wood samples. The physical (mass/density loss, dimensional stability, color change, and surface roughness), mechanical (flexure test and compressive strength), morphological, thermal, and structural properties of the heat-treated wood were examined. It was determined that the heat treatment parameters can be optimized using the DIC method. The test results showed that although heat treatment can provide improved physical and thermal properties, it caused micro-crack formations and collapses in the wood cells. As a consequence, the mechanical properties of the heat-treated wood materials decreased with the heat treatment process. There were slight differences in the curves of the samples according to Fourier infrared and X-ray diffraction analyses. Morphological characterization showed that the heat treatment triggered large cracks in the cell wall and lumens and the morphological structure of heat-treated wood was affected at large percentages.
The aim of this paper was to investigate the effects of wood flour on the mechanical, morphologic... more The aim of this paper was to investigate the effects of wood flour on the mechanical, morphological and thermal properties of poly (L-lactic acid) (PLA)-chitosan biopolymer composites produced by compression molding. The composites were characterized by a combination of mechanical properties, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The addition of chitosan to PLA matrix reduced the tensile strength from 57,1 MPa for pure PLA to 34,3 MPa for 5% chitosan and 11,5 MPa for 10% chitosan, and the flexure strength from 72,3 MPa for pure PLLA to 30,4 MPa for 5% chitosan and 24,6 MPa for 10% chitosan. The change trend in the young's modulus was found to be similar as compare with the tensile strength. However, the flexure modulus generally increased with the addition of the chitosan as comparison with pure PLA. The mechanical properties of the PLA-chitosan blends with wood flour were found to be lower than theirs of the pure PLA. According to SEM images, some holes and small voids at various diameters on the fractured section of the all composites were seen. T onset , T 10% , T 50% , T 85% of the pure PLA decreased with the addition of both chitosan and wood flour. Thermal stability of the PLA-chitosan blends was determined to be better than the PLA-chitosan composites with wood flour.
İnsanlık tarihi boyunca en yaygın hammadde ahsap olmuştur. Sanayinin gelişmesiyle tüketim artmış ... more İnsanlık tarihi boyunca en yaygın hammadde ahsap olmuştur. Sanayinin gelişmesiyle tüketim artmış ve alternatif malzemelerin gerekliliği doğmuştur. Bu gerekliliğin bir sonucu olarak, düşük kaliteli ashap malzemenin yapıştırılmasıyla lamine malzemeler elde edilmiştir. Elde edilen bu materyal birçok alanda kullanıma başlamıştır. Ahşap lamine malzemelerin iç ve dış ortam şartlarında uzun süre dayanıklı kalabilmesini sağlamak için ahşap malzeme çeşitli emprenye maddeleriyle muamele edilmektedir. Bu işlem sonrası lamine malzemenin üretilmesi süresince rutubet arttığı için ahşap malzemenin bir birlerine tutunma yetenekleri düşmektedir. Bu durumda lamine malzemelerin de yapışma önemli bir durum olmaktadır. Yapışma direncinin artmasıyla iyi malzemeler elde edilmektedir. Tam tersi durumunda ise çeşitli hatalar oluşmaktadır. Bu hataları engellemek için yapışmayı etkileyen faktörlerin bilinmesi önem arz etmektedir. Çalışmada yapışmayı etkileyen en önemli faktörler araştırılmıştır.
Düzce Üniversitesi bilim ve teknoloji dergisi, Mar 7, 2016
Termoset bir polimer olan epoksi, birçok alanda kullanımı olan bir materyaldir. Suya, aside ve al... more Termoset bir polimer olan epoksi, birçok alanda kullanımı olan bir materyaldir. Suya, aside ve alkaliye direnci çok yüksek, zamanla direnç özelliğini kaybetmez ve bu yüzden birçok materyalin ya da kompozitin hazırlanmasında kullanılabilmektedir. Özellikle yüzey kaplamalarında ve yüzey özelliklerinin iyileştirilmesinde farklı katkı maddeleriyle birlikte kullanılabilmektedir. Bu çalışmada; lamine kayın panellerin fiziksel, mekanik ve yüzey morfolojisi üzerine Mikrofibril selüloz (MFC), Nanofibril selüloz (NFC), pamuk (C) ve α-selüloz (AC) katkılı epoksi tutkalının etkileri araştırılmıştır. Lamine malzemeler 5 katmanlı olarak Doğu kayını (Fagus orientalis) odunu kullanılarak yapılmıştır. Analiz sonuçlarına göre epoksi'ye eklenen farklı katkı maddelerinin, lamine malzemelerin yoğunluk değerlerini kısmen yükselttiği belirlenmiştir. Yoğunluk değerlerine göre tam kuru rutubette NFC ilaveli lamine kompozitlerin yoğunluğu 0.70 gr/cm³, hava kurusu rutubette MFC'li kompozitlerin 0.74 gr/cm³ ve %100 rutubette ise kontrol örneklerinde 0.90 gr/cm³ olarak belirlenmiştir. Elde edilen mekanik özelliklere bakıldığında sırasıyla en yüksek eğilme direnci, MFC içeren kompozitlerde 118,5 MPa; eğilmede elastikiyet modülü ve basınç direnci ise C'li numunelerde 9385 MPa ve 66.81 MPa Olarak belirlenmiştir. Elektron mikroskobu yardımıyla yapılan yüzey analizlerinde ise katkı maddelerinin yüzeyde tutunmayı artırarak mekanik özellikleri yükselttiği belirlenmiştir.
e coating of wood and wood panel surfaces basically serves for surface protection and its surface... more e coating of wood and wood panel surfaces basically serves for surface protection and its surface can be improved at various user areas. Di erent application methods are used for the coating of MDF surface. ese are methods such as curtain coating, spraying, rolling, knife, etc. In this study, suitability of pigment coating method instead of the traditional surface coating methods used for coating MDF panels and the e ects of re retardants on surface properties of MDF coated by the best appropriate coating mixture was investigated. Calcite and clay were used as coating pigment and latex, urea formaldehyde, and melamine formaldehyde were used as adhesive. Coating/adhesive mixture obtained was applied to MDF panels with knives. Before the analysis, test samples were put to condition room and they were kept in there for 1 week. According to the results obtained, the best appropriate coating material was found as calcite. 22% concentrated melamine formaldehyde as adhesive and 0.25 mm as coating thickness was determined better than other combinations. Borax, boric acid and zinc borate as re retardant were added to calcite /melamine formaldehyde with 22% mixture. So, the e ects of re retardant on surface characterization were determined. Surface properties of coated MDF panels tested were found lower than standard requirements except for abrasion resistance.
The objective of this study is to evaluate the effect of décor paper and resin type on physical p... more The objective of this study is to evaluate the effect of décor paper and resin type on physical properties, mechanic properties, and surface quality properties of particleboards coated with décor papers impregnated by using different resin. White oak, New wenge and common maple pattern decor papers impregnated with urea formaldehyde (UF), melamine formaldehyde (MF) and urea-melamine formaldehyde (UF+MF) were used as coating materials. Particleboard surface was laminated with these coating materials by hydraulic press. As a result, specimens coated with MF-impregnated papers showed better performance than those coated with UF and UF+MF-impregnated papers. Resin type and paper pattern affected the physical, mechanical (with exception of tension strength), and surface properties (especially cigarette burn and abrasion) of coated particleboards. Physical and mechanical properties of coated particleboard were significantly improved compared to non-laminated particleboards. It was found that paper pattern affected the surface properties, such as impact, scratch, and abrasion, resistance to staining and cigarette burn. However, it did not change the cracking and steaming properties of the coated samples. After the coating process, it was determined that cigarette burn, abrasion, impact, and scratch performances were among 1 to 3 grade, lp:10-35, Fp:210-340/100-150, and 2 to 5 grade, respectively.
Polyvinyl acetate (PVAc) is a thermoplastic polymer widely used in the furniture industry. It has... more Polyvinyl acetate (PVAc) is a thermoplastic polymer widely used in the furniture industry. It has many advantages such as easy processing, cheap, biodegradable; but, resistance to water and hot medium is not enough to the application area. In this study, the effect of nano-TiO 2 and nano-SiO 2 on bonding performance and structural properties of PVAc were investigated. Bonding strength with block shear test and structural properties with thermogravimetric analysis-TGA, X-ray diffraction-XRD, and transmission electron microscopy-TEM of PVAc were determined. The obtained results showed that bonding strength with cooperating both TiO 2 and SiO 2 for 1% and 2% were improved. XRD and TEM results proved to be the homogenously interactions for 1% and 2% between nano fillers and matrix. TGA results showed that thermal stability of PVAc blends was largely improved.
In this study, we investigated the effect of fire retardants (FRs) on the combustion performance ... more In this study, we investigated the effect of fire retardants (FRs) on the combustion performance of medium-density fiber boards (MDFs) that were coated with mixtures of water, binder, calcite, and various FRs (FR coatings). We used MDF panels, calcite as the coating pigment, melamine formaldehyde as the binder, and FRs, including borax (BX), boric acid (BA), and zinc borate (ZB), to investigate the effects on the properties of the test boards. According to the results of combustion properties of coated MDFs with FR coatings, BA presented the highest stability, followed by BX and ZB, respectively. It was also found that the fire resistance of coated MDFs was better than that of uncoated MDF panels. For samples coated with FR coatings, the lowest burning temperature of 3% BA coatings was about 216 °C, and the highest burning temperature of 1% BX coatings was found as approximately 271 °C. The lowest mass losses were 35.5% for BA and 36% for BX. As a result, both surfaces of MDF panel can be coated with a mixture of calcite and FR, thereby improving the combustion properties of the MDFs. BA coatings showed to be have better thermal properties than both BX and ZB coatings.
Thermal instability is the one of the most important disadvantages of wood since it begins to dec... more Thermal instability is the one of the most important disadvantages of wood since it begins to decompose at a low temperature (˃110 °C). Many scientists, past and present, have conducted studies aimed at improving the thermal stability of wood. The aim of this study was to impregnate wood with nano-sized boron nitride (NBN) to improve its thermal stability and to investigate the changes in the properties of Scots pine (Pinus sylvestrist), Ash (Fraxinus exelsior), and Iroco (Chlorophora excelsa) woods after the impregnation. The effects of the impregnation with NBN also were investigated on the heat-treated woods. The impregnation was conducted with using full-cell method in a chamber under a pressure of 0.6 MPa for 1 h. Densities at 0% and 12% moisture content (MC), mechanical properties, color changes, thermal stability, and scanning electron microscopy (SEM/EDAX) analysis were determined. The test results showed that the impregnation of wood with NBN increased generally the flexural strength and elasticity of modulus at bending, but the NBN impregnation decreased generally the compression strength except for ACI, ATWI, IC, and ICI. It was also determined that the changes in density and color were statistically different after the impregnation. According to the SEM/EDAX results, deposits of nano-sized boron nitride were found inside the cell wall and on the pits. But the deposits were also determined in inside structure of the wood with EDAX analysis. Thermal stability in T 10% and T 50% of wood was found to improve after the impregnation with NBN. TG/DTG and DTA values for some samples were found to fluctuate due to the heterogeneous dispersion of the NBN in the wood.
Journal of Bartin Faculty of Forestry, Dec 15, 2020
In this study, the physical and mechanical properties of medium density fiber boards (MDF) produc... more In this study, the physical and mechanical properties of medium density fiber boards (MDF) produced with urea formaldehyde adhesive reinforced with nano-boron nitride (BN) and nano-titanium dioxide (TiO2) were investigated. 0.5% and 1.5% nano-filled urea formaldehyde adhesives were used in the production of test samples. The density, thickness swelling, water uptake, internal bond strength, bending strength, modulus of elasticity in bending and SEM analysis of the boards prepered were determined. According to the laboratory tests conducted, there was no significant change in the density of the boards after nano filling. Physical properties such as water intake and thickness swelling were determined to decrease with the addition of nano particles. The mechanical properties of the boards increased with the addition of both nano-BN and TiO2. According to the a results of thermogravimetric analysis, it has been determined that the thermal stability of urea formaldehyde adhesive with TiO2 is increased and maximum mass loss temperatures are higher than the addition of nano-BN. The morphological structure of the urea formaldehyde adhesive was visualized with an electron microscope, and the nanoparticle dispersions were displayed and the particles were also analyzed by EDAX analysis. As a result, it has been determined that MDFs prepared with nanoparticle adhesives have improved physical, mechanical and thermal properties. Particularly, all samples with nano particles have been achieved the standards required in their mechanical properties. As a result, it can be sad that the adding nano-particles have positive effect on the physical and mechanical properties of the panels.
Biopolymer blends of polyhydroxybutyrate and polylactic acid reinforced with cellulose nanofibril... more Biopolymer blends of polyhydroxybutyrate and polylactic acid reinforced with cellulose nanofibrils Deniz Aydemir (Conceptualization) (Methodology) (Data curation) (Formal analysis) (Writing -original draft), Douglas J. Gardner (Funding acquisition) (Project administration) (Writing -review and editing)
In this paper, the effect of cellulose nanofibrils (CNFs) loading levels on the conventional and ... more In this paper, the effect of cellulose nanofibrils (CNFs) loading levels on the conventional and dynamic mechanical, morphological, thermal and rheological properties of the polyhydroxybutyrate (PHB) biopolymers were studied. According to the results, adding CNFs from 1% to 20% generally didn’t provide any improvement in the flexural, tensile and izod impact strength attributable to void formation and pulling out and agglomeration of nanofibrils in the matrix, which was observed during morphological characterization, however adding CNFs substantially increased both flexural and tensile modulus of elasticity. Thermal analysis showed that adding CNFs generally decreased degradation at high temperatures of the biopolymer nanocomposites (BNCs) The addition of CNFs at 1, 10 and 20% increased the E' and E'' of neat PHB but the other loadings decreased them, and tan delta increased with CNF loadings of 3, 5, 10 and 20%, and finally adding CNFs didn’t change the rheological behavior of the composites.
Ahşap malzemenin (özellikle yapı sektöründe) olabildiğince homojen olması istenmektedir. Ağaçları... more Ahşap malzemenin (özellikle yapı sektöründe) olabildiğince homojen olması istenmektedir. Ağaçların büyüme dönemlerinin ilk yıllarında (yaklaşık olarak 5 ile 20 yıl arası) oluşan genç odun bu homojenliğin bozulmasına neden olabilir. Çünkü genç odun anatomik ve teknolojik özellikler bakımından olgun odundan (genç odundan sonra oluşan ve daha yüksek direnç değerlerine sahip olan kısım) daha farklı özelliklere sahiptir. Ülkemizde özellikle kereste endüstrisi olmak üzere, orman ürünleri sanayinde kullanılan ağaçların (çam türleri, karaağaç, kızılağaç, kayın vb.) genç odun dokusunun özelliklerinin belirlenmesi büyük önem taşımaktadır. Zira genç odun dokularının mekanik özellikleri olgun odundan daha düşüktür. Bu nedenle doğal genç ormanlardan ya da plantasyonlardan üretilen ağaç malzemelerde beklenmedik sonuçlar ortaya çıkarabilir. Bu çalışmada, ağaçların genç ve odun dokularının fiziksel, kimyasal ve mekanik özelliklerinin karşılaştırıldığı çalışmalar mercek altına alınarak yorumlanmıştır. Bu sayede, odun esaslı malzemelerin teknolojik özelliklerine, ağaç yaşının etkisi bilimsel olarak ortaya konmaktadır.
The aim of this study was to investigate some of the physical, mechanical, thermal and morphologi... more The aim of this study was to investigate some of the physical, mechanical, thermal and morphological properties of wood fl our and cellulose fi ber fi lled polypropylene composites. Polypropylene as a polymer matrix and wood fl our and cellulose fi bers were used as reinforcing fi llers to prepare the composites by using a single screw extruder. Physical properties such as density, mechanical properties such as fl exure strength and fl exure modulus, tensile strength and tensile modulus, and impact strength, thermal behavior with thermogravimetric analysis (TGA/DTA), and morphological characterization with scanning electron microscopy (SEM) of the composites were determined. The density of the composites was found to increase with the addition of fi llers. The mechanical properties of the composites showed that the fl exure and tensile strength for the composites with wood fl our was higher than the composites with cellulose fi bers, whereas fl exure and tensile modulus, and impact strength for the composites with cellulose fi bers was found to have higher values as compared to the composites with wood fl our. SEM pictures showed that particles and fi bers dispersed to different locations in polypropylene matrix. According to the TGA results, thermal degradation of all the composites was found to be lower compared to neat polymer.
Mehmet Akif Ersoy Üniversitesi Fen Bilimleri Enstitüsü Dergisi
Ahşabın tüm fiziksel, mekanik ve estetik özellikleri, heterojen biyolojik hücre yapısıyla oluşur.... more Ahşabın tüm fiziksel, mekanik ve estetik özellikleri, heterojen biyolojik hücre yapısıyla oluşur. Ahşap incelemelerinde, mikroskobik ve hatta ultrastrüktürel düzeyde ahşap kırılmasının doğasına ilgi artmıştır. Taramalı Elektron Mikroskobu (SEM), ahşap yapı araştırmalarını mümkün kılan en güçlü tekniklerden biri gibi görünmektedir. Çalışmada Doğu çınarı (Platanus orientalis L.) odunu kullanılmıştır. Hazırlanan numunelere çekme ve basınç direnci testleri uygulanmıştır. Mekanik testleri yapılan örneklerin deforme olan bölümlerinden kesitler alınmıştır. Bu kesitlerde Taramalı Elektron Mikroskobu incelemeleri yapılmış ve hücre görüntüleri mikrograflar kullanılarak analiz edilmiştir. Mikrograflarda, çekme direnci testleri sonucu hücre yapılarında meydana gelen parçalanarak kopma ve hücrelerin parçalanma şekilleri, basınç direnci testleri sonucu hücre duvarlarındaki çatlaklar, ayrılmalar ve kırıklar açıkça görülebilmiştir.
e coating of wood and wood panel surfaces basically serves for surface protection and its surface... more e coating of wood and wood panel surfaces basically serves for surface protection and its surface can be improved at various user areas. Di erent application methods are used for the coating of MDF surface. ese are methods such as curtain coating, spraying, rolling, knife, etc. In this study, suitability of pigment coating method instead of the traditional surface coating methods used for coating MDF panels and the e ects of re retardants on surface properties of MDF coated by the best appropriate coating mixture was investigated. Calcite and clay were used as coating pigment and latex, urea formaldehyde, and melamine formaldehyde were used as adhesive. Coating/adhesive mixture obtained was applied to MDF panels with knives. Before the analysis, test samples were put to condition room and they were kept in there for 1 week. According to the results obtained, the best appropriate coating material was found as calcite. 22% concentrated melamine formaldehyde as adhesive and 0.25 mm as coating thickness was determined better than other combinations. Borax, boric acid and zinc borate as re retardant were added to calcite /melamine formaldehyde with 22% mixture. So, the e ects of re retardant on surface characterization were determined. Surface properties of coated MDF panels tested were found lower than standard requirements except for abrasion resistance.
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