Browsing by Author "Ates S."

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Characterisation of surfaces coated with different nanocellulose-based suspensions
(2023-01-01) Durmaz E.; Ates S.
In this study, plywood surfaces were coated with different nanocellulose-based suspensions. Moreover, we analysed the effect of boric acid (BA), polyvinyl alcohol (PVA) and melamine formaldehyde (MF) on surface properties for some coating suspensions. According to the results, gloss values of plywood surfaces coated with nanocellulose-based suspensions changed depending on nanocellulose type, matrix type and number of coating layers. It was determined that coated plywood surfaces had low and medium gloss properties. When surface hardness values of coated plywood samples were analysed, it was observed that increasing the number of coating layers and addition of different kind of matrixes increased surface hardness values of the coated wooden surfaces up to the highest level (7H). Furthermore, it was determined that addition of BA, PVA and MF with various concentrations to nanocellulose-based suspensions declined water contact angles (WCA) of wooden surfaces coated with these solutions by reducing surface hydrophobicity.
Characterization and evaluation of Paulownia elongota as a raw material for paper production
(2008-11-19) Ates S.; Ni Y.; Akgul M.; Tozluoglu A.
Paulownia elongota, one of the most fast growing species of the world, was evaluated as raw material for pulp and paper production. The chemical, morphological and anatomical aspects of paulownia wood were determined. The lignin, holocellulose and α-cellulose contents in P. elongota wood were comparable to those of some common non-wood and hardwood raw materials. Different chemical pulping procedures were applied to P. elongota wood to evaluate its pulping potential. Paper strength properties and acidic group content bound to the cell wall were determined. The alkali solubility, water solubility and alcohol-benzene extractive content were higher than those from wood and most nonwoods. The fiber length of 0.83 mm was observed, which is close to low end of the hardwoods but fiber diameter was very wide, similar to that of softwoods. The pulpability of paulownia wood was also studied. The pulp yield and viscosity were very low and the kappa numbers were high. The strength properties were comparable to those of some wood and non-wood pulps. Although, paulownia pulps are considered as low quality materials, it can be used for paper production when mixed with long fibrous materials. © 2008 Academic Journals.
Chemical composition and antioxidant properties of some industrial tree bark extracts
(2019-08-01) Hamad A.; Ates S.; Olgun Ç.; Gür M.
Wood bark is a residue of forestry production that is used as a fuel source. The chemical composition of tree bark is similar to that of the harvested wood, and it contains a variety of useful compounds. To determine the chemical composition and antioxidant activities of different barks, fir (Abies nordmanniana), beech (Fagus orientalis), pine (Pinus sylvestris), poplar (Populus alba), and oak (Quercus robur) barks were selected because they are used for industrial purposes in Turkey. The dried bark powders were extracted using a 65:35 methanol-water mixture (v/v) to determine the total phenolic content, the flavonoid content, and the antioxidant properties (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), metal chelating, and H2O2 scavenging). The flavonoid components were analyzed by high performance liquid chromatography (HPLC) and extracted by hexane to analyze the volatile components by gas chromatography-mass spectrometry (GC-MS). The poplar bark extracts had the highest total phenolic content, highest total flavonoid content, and highest antioxidant content. The poplar bark extracts were rich in myricetin (87.761 mg/L), which is a flavonoid with rich antioxidant properties. The presence of valuable extracts suggests that barks may have uses as valuable raw materials for chemical applications such as cosmetics, perfumes, and food preservatives.
Chemical contents and antifungal activity of some durable wood extractives vs. Pleurotus ostreatus
(2015-01-01) Ates S.; Gür M.; Özkan O.E.; Akça M.; Olgun Ç.; Güder A.
The total phenolic content (TPC), total flavonoid content (TFC), phenolic compounds, and antifungal activity of olive (Olea europaea var. sylvestris) and juniper (Juniperus foetidissima) sapwood and heartwood extractives were examined. The extractives were obtained using methanol solvents. The different compounds in extractives were identified and quantified. The antifungal activities of different parts of the olive and juniper wood extractives were determined in vitro. Pleurotus ostreatus mycelium was used for the antifungal activity experiment. Extractive compounds obtained from olive and juniper woods were found to be effective, natural antifungal agents.
Chemical, morphological and anatomical properties and evaluation of cotton stalks (Gossypium Hirsutum L.) in pulp industry
(2010-06-01) Tutus A.; Ezici A.C.; Ates S.
In this study, chemical composition and morphological properties of cotton stalks growing in Turkey were investigated. Typical chemical properties determined were the amount of holocellulose, α-cellulose, cellulose, lignin, ash, silica, solubility of cold and hot water and 1% soda and alcohol-benzene. The holocellulose, a-cellulose, cellulose, lignin contents and solubility of cold and hot water and 1% soda and alcohol-benzene in cotton stalks were determined similar to those of some common non-wood and hardwood raw materials. Also, sodium borohydride (NaBH4) modified kraft pulping was performed by using cotton stalks and the effects of NaBHinf4/inf addition on the total pulp yield and chemical properties of pulps were investigated. In order to determine the optimum cooking parameters, 30 different laboratory experiments were performed. It was noted that the increasing level of NaBH4 improved the screened pulp yield, pulp viscosity and degree of polymerization, reduced the kappa number. Consequently, total pulp yield was increased (15.66%) by NaBHinf4/inf addition. Pulp viscosity and degree of polymerization were found to be higher than those of kraft one by about 1.60 and 1.73%, respectively. However, kappa number of NaBHinf4/inf added to kraft pulp is lower (15.86%) than those of kraft one. © 2010 Academic Journals.
EFFECT OF NANOCELLULOSE TYPE AND MATRIX MATERIAL ON PRODUCTION OF NANOCOMPOSITE FILMS
(2023-05-01) Durmaz E.; Ates S.
Effects of heat treatment on calabrian pine (Pinus brutia Ten.) wood
(2009-08-01) Ates S.; Akyildiz M.H.; Ozdemir H.
In this study, the effects of heat treatment on some physical, mechanical, chemical properties, and cellulose crystallinity of calabrian pine (Pinus brutia Ten.) were evaluated. Wood specimens were treated with heat under atmospheric pressure at three different temperatures (130, 180, and 230 °C) and two different time levels (2 and 8 h). Air-dry density (Dm), oven-dry density (D0), shrinkage (β), swelling (α), fiber saturation point (FSP), compression strength parallel to grain (σc//), bending strength (σb), modulus of elasticity (MOE) in bending, equilibrium moisture content (EMC), holocellulose, and alcohol solubility were decreased, whereas 1% NaOH solubility and lignin content were increased, depending on the heating temperature and time. Cellulose crystallinity of the samples was not changed significantly. 130 °C showed a minimal effect; on the other hand, 230 °C showed a maximum effect on all properties of the treated wood. That's why, for the heat treatment process, 130 °C for 2 h should be applied in situations where mechanical properties such as modulus of elasticity, compression strength, bending strength, and hardness are important. However, 230 °C for 2 h should be used in situations where it is preferred to obtain favorable physical properties, such as density, shrinkage, swelling, and moisture content.
Effects of heat treatment on some properties of MDF (medium-density fiberboard)
(2017-05-27) Ates S.; Kara H.; Olgun C.; Ozkan O.
This work investigated some mechanical, physical and free formaldehyde emission properties of heat-treated MDF. For this purpose, MDF panels were subjected to varying heat treatment temperatures (155°C, 165°C and 175°C), durations (2.5 h., 3.5 h. and 4.5 h.) and waiting times after hot pressing (30 min., 120 min. and 600 min). Thickness swelling (TS), water absorption (WA), free formaldehyde emission (FFE), bending strength (BS), modulus of elasticity (MOE), tensile strength perpendicular to fibers (TSPF) for treated and untreated samples were tested and evaluated statistically. Consequently, after the heat treatment values of tensile strength, bending strength and modulus of elasticity were almost negatively affected relatively, but the thickness swelling and water absorption and quantities of free formaldehyde were improved positively of MDF samples.
Effects of the endoxylanase treatment on fiber characteristics, brightness stability and strength properties of bleached wheat straw pulp
(2009-12-01) Ates S.; Ni Y.; Atik C.
The pretreatment of soda-anthraquinone (AQ) wheat straw pulp with purified endo-( 1,4)-β-xylanase was studied. Different xylanase dosages (0, 2, 20 and 100 IUg-1) were applied to the pulp before an ECF (Elemental Chlorine Free) bleaching sequence. The fiber characteristics, brightness stability and strength properties of the obtained pulps were determined. The results showed that the fiber characteristics were not significantly affected by the enzyme pretreatment. On the other hand, the xylanase pretreatment lowered the strength properties of the pulp. A slight improvement in lignin removal was observed, thus improving pulp bleachability, the results agreeing with those obtained on wood pulps. Furthermore, higher paper brightness stability was obtained by the xylanase pretreatment, explained by the removal of the metal ions from the pulp samples.
Fungal pretreatment of wheat straw and its effect on the soda-AQ pulps
(2009-01-01) Fatehi P.; Ates S.; Ni Y.
In this study, the effects of Ceriporiopsis subver-mispora (C.S.) and Phlebia subserialis (P.S.) fungal pre-treatments of wheat straw on the pulp and paper properties of soda-AQ pulps were investigated. The results showed that both fungal pretreatments enhanced delignification and carbohydrate degradation. Also, the P.S. pretreatment increased the brightness and decreased the kappa number and viscosity of pulps more than the C.S. pretreatment. Generally, the bulk, brightness, and tear index of papers increased by the fungal pretreatments, while the tensile and burst indices decreased at all refining levels applied. The C.S. pretreatment had more pronounced effect than the P.S. pretreatment on increasing the bulk and decreasing the tensile and burst indices. Furthermore, cationic-modified poly(vinyl alcohol), CPVA, was used as a dry strength additive to compensate for the loss in the strength properties. The results showed that, upon similar CPVA adsorption, the strength properties of the papers made of the C.S. pretreated fibers were improved more than those of the P.S. pretreated fibers. The application of CPVA on unrefined or refined fungal pretreated fibers showed the possibilities of decreasing the basis weight of papers to achieve the same tensile strength.
Impact of cationic polyvinyl alcohol on properties of papers made from two different pulps
(2009-07-01) Fatehi P.; Ates S.; Ward J.; Nl Y.; Xiao H.
In this study, the effect of cationic polyvinyl alcohol (CPVA), with charge density of 0.4 meq/g, on the properties of papers made from a bleached softwood sulfite pulp and from an unbleached straw pulp was systematically investigated. The CPVA adsorbed more on the unbleached straw pulp than on the bleached sulfite pulp. Increasing the dosage of CP VA significantly increased the strength properties of the papers made from the unrefined bleached sulfite pulp, but produced only a limited increase in the strength properties of the papers made from the unrefined unbleached straw pulp. Refining was more effective at changing the characteristics of fibres and papers made from the bleached sulfite pulp than those from the unbleached straw pulp, regardless of the CPVA application. At the same sheet density, applying CPVA increased the tensile index of papers made from the unbleached straw pulp more significantly than that of papers made from the bleached sulfite pulp. Over the CPVA dosage range investigated, applying CPVA was more effective than refining at enhancing the strength properties of the papers made from the unbleached straw pulp. In contrast, refining was more effective than applying CPVA at enhancing the strength properties of the papers made from the bleached sulfite pulp. The effect of CPVA on the structural and optical properties of the papers was comprehensively assessed.
Mass balance of silica in straw from the perspective of silica reduction in straw pulp
(2012-08-01) Atik C.; Ates S.
The high silica content of wheat straw is an important limiting factor for straw pulping. High silica content complicates processing and black liquor recovery, wears out factory installations, and lowers paper quality. Each section of wheat straw has different cells and chemical compositions and thus different silica content. In this work, the silica content of balled straw samples were examined according to their physical components, including internodes, nodes, leaves (sheath and blade), rachis, grain, other plant bodies, and other plant spikes. Mass distribution of silica was determined by a dry ashing method. Half (50.90%) of the silica comes from leaves, and its mechanical separation will reduce the silica content in wheat straw pulp significantly. Destroying silica bodies by sonication will increase the strength properties of straw pulp.
Nanocellulose in Paper and Board Coating
(2022-01-01) Tozluoglu A.; Ates S.; Durmaz E.; Sertkaya S.; Arslan R.; Ozcelik O.; Candan Z.
With the increase in social environmental consciousness, the interest in the production of cellulose-based nanomaterials from renewable natural resources has swiftly increased in recent years. Renewable nanotechnology displays distinguished properties of traditional petroleum-based materials, and also creates new properties such as renewability, biocompatibility, and biodegradability. Nanocellulosic materials allow the design of special materials with high performance that can eliminate present environmental and sustainability problems. Growing interest in such new generation products, which are called bio-based nanomaterials, will substitute conventional petroleum-based materials because of fluctuations in oil prices and scarcity of sources. The generation of these new nanomaterials will lead to the production of materials with high performance while eliminating environmental problems. This chapter presents a unique literature survey on the production methods, characterization, and modification of nanocellulose, and also on the effects of nanocellulose as a coating and additive material on paper and board.
Pretreatment by ceriporiopsis subvesmispora and phlebia subserialis of wheat straw and its impact on subsequent soda-AQ and kraft-AQ pulping
(2008-01-01) Ates S.; Ni Y.; Atik C.; Imamoglu S.
Pretreatments of wheat straw with two different lignindegrading fungal cultures Ceriporiopsis subvesmispora and Phlebia subserialiswere carried out and their effects on sodaAQ and kraftAQ pulping were studied. After two weeks of biotreatment of the wheat straw, both fungus were found to be suitable for biochemical pulping. The fungal pretreatment decreased the kappa number by as much as 24% and the unbleached pulp brightness increased by about 7% at a constant yield. Furthermore, the biopretreatment increased the brightness of the fully bleached pulp by about 1 ISO% point. This can apparently reduce the amount of the chemicals used in the bleaching process. The results on the sugar analysis of the pulps showed that in terms of carbohydrate composition, there were no significant differences between the biotreated and control pulps. However, the strength properties of the unbleached and bleached chemical straw pulps decreased slightly after the fungal pretreatment. This is different from reported results that the strength properties of mechanical pulps were improved after the fungal pretreatment. There was no difference of the two whiterot fungal species, Ceriporiopsis subvesmispora and Phlebia subserialis in term of their effect on the strength properties. © 2008 Bucharest University Printed in Romania.
Pulp and paper production from spruce wood with kraft and modified kraft methods
(2010-03-15) Tutus A.; Ates S.; Deniz I.
In this study, kraft and modified kraft pulping methods were applied for spruce (Picea orientalis) wood collected from the Black Sea Region of Turkey. Fiber properties, carbohydrate contents, strength and optical properties of resultant paper were included to determine the properties of these pulp samples. Optimum kraft, kraft-borohydride (NaBH4), kraft-anthraquinone (AQ) and kraft-ethanol pulping conditions were determined. After determining screened yield, kappa number, viscosity, fiber length, fiber coarseness, -cellulose, holocellulose, lignin and ash content, breaking length, tear indexes and burst indexes of the obtained pulp samples, the differences of SEM image of each pulp sample were captured and evaluated. The results indicated that kraft-AQ pulps from spruce wood exhibited better characteristics than the other pulp samples with lower kappa number, higher paper strength properties and optical properties. However, kraft-NaBH4 method gave pulps with closer characteristics to kraft-AQ and also gave a higher screened yield and -cellulose ratio than the others. © 2010 Academic Journals.
Technological and chemical properties of chestnut (Castanea sativa Mill.) wood after heat treatment
(2010-06-18) Ates S.; Akyildiz M.H.; Özdemir H.; Gümüşkaya E.
This study was performed to determine the effects of heat treatment on air-dry density (Dm), oven-dry density (D0), shrinkage (β), swelling (α), fiber saturation point (FSP), compression strength parallel to grain (σc//), bending strength (σb), modulus of elasticity (MOE) in bending, brinell-hardness (HB), equilibrium moisture content (EMC), chemical content and cellulose crystallinity of chestnut (Castanea sativa Mill.) wood. Wood samples were treated to heat at three different temperature (130, 180 and 230°C) and two different time level (2 and 8 h) under atmospheric pressure and presence of air. Dm, D0, β, α, FSP, EMC, σc//, σband MOE were decreased by heat treatment. Lignin content, 1% NaOH and alcohol solubility values increased with depend on the heating temperature and time. Cellulose crystallinity of the samples was not changed significantly. Consequently, for heat treatment process, 130°C for 2 h should be applied in place where mechanical properties are important. However, 230°C for 2 h should be used in place where preferred physical properties. Heat-treated chestnut woods could be utilized by using proper heat treatment techniques in outdoors and indoors applications for several purposes such as musical instruments, kitchen furniture, garden furniture and windows frames. © 2010 University of Bucharest.
Technological and chemical properties of heat-treated Anatolian black pine wood
(2009-06-03) Akyildiz M.H.; Ates S.; Özdemir H.
In this study the effect of heat treatment on air-dry density (D m), oven-dry density (D0), shrinkage (β), swelling (α), fiber saturation point (FSP), compression strength parallel to grain (σc//), bending strength (σb), modulus of elasticity (MOE) in bending, Brinell-hardness (HB), equilibrium moisture content (EMC), chemical content and cellulose crystallinity of Anatolian black pine [Pinus nigra J.F. Arnold subsp. nigra var. caramenica (Loudon) Rehder] was evaluated. Specimens were subjected to heat under atmospheric pressure at 3 different temperature (130, 180 and 230°C) and 2 different time levels (2 and 8 h). The value of Dm, D0, β, α, FSP, EMC, σc//, σb, MOE, holocellulose, 1% NaOH and alcohol solubility decreased, whereas, lignin content increased depending on the heating temperature and the time. Cellulose crystallinity of the specimens was not changed significantly. 130°C showed minimum effect, on the other hand, 230°C showed maximum effect on all properties of treated wood. Accordingly, for heat treatment process, 130°C for 2 h should be applied in place where mechanical properties are important. However, 230°C for 2 h should be used in place where a physical property is preferred. Consequently, heat treated Anatolian black pine woods could be utilized in applications for several purposes such as kitchen furniture, outdoor furniture and windows frames. © 2009 Academic Journals.