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    Adhesive characteristics and bonding performance of phenol formaldehyde modified with phenol-rich fraction of crude bio-oil
    (Taylor & Francis Ltd, 2015) Aslan, Metin; Ozbay, Gunay; Ayrilmis, Nadir
    Commercial phenol-formaldehyde (PF) adhesive was gradually substituted by increasing amount of the phenol-rich fraction (PRF) of crude bio-oil up to 40wt%. The effect of substitution level of the PRF on the chemical, curing, morphological scanning electronic microscope(SEM), and bonding characteristics of the PF adhesive was determined. The tensile-shear strength of single lap-joint wood specimens bonded with the modified PF adhesives was investigated under indoor and outdoor exposure conditions. The chemical composition of the PRF was investigated using some chromatographic and spectroscopic techniques. Further structural analysis of PRF-modified PF adhesives was determined using Fourier transform infrared spectroscopy(FTIR). The PRF resol had a similar molecular structure to commercial pure phenol resol adhesive. The PRF could be partially substitute for the petroleum-based phenol in commercial PF adhesives with inexpensive phenols derived from lignocellulosic wastes.
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    Bonding performance of wood bonded with adhesive mixtures composed of phenol-formaldehyde and bio-oil
    (Elsevier Science Bv, 2015) Ozbay, Gunay; Ayrilmis, Nadir
    This study investigated the bonding performance of phenol-formaldehyde (PF) adhesive containing different amounts of pyrolysis bio-oil. The amount of bio-oil in the PF adhesive was gradually increased to 40 wt%. Pine wood sawdust was converted into renewable chemical feedstock for the production of bio-based phenolic adhesive. The chemical composition of the bio-oil, and the viscosity and pH of each type of adhesive mixtures were analyzed. The bonding performance of the adhesive mixtures was determined using single lap-joint tensile specimens. The results showed the bond quality of the PF adhesive containing 20 wt%, bio-oil was better than that of the commercial PF adhesive under dry conditions. The PF adhesive containing 20 wt% the bio-oil met the requirements for durability classes of 1-3 specified in EN 12765, (2002). Environmentally friendly adhesives from biomass can be used as a substitute for existing petroleum based PF adhesive in the manufacture of wood-based panels. (C) 2014 Elsevier B.V. All rights reserved.
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    Effects of Catalysts on Modulus of Rupture and Chemical Structure of Heat-Treated Wood
    (Zagreb Univ, Fac Forestry, 2018) Ozcifci, Ayhan; Kokten, Erkan Sami; Ayrilmis, Nadir; Ozbay, Gunay; Altun, Suat
    Heat treatment process, which is widely used in the wood industry, has shown some negative effects on the mechanical strength of wood. The objective of this study was to investigate the effects of catalysts on the modulus of rupture (MOR), mass loss and chemical structure of heat-treated Scotch pine (Pinus sylvestris L.) samples. For this purpose, some catalysts (50 % NaOH and 47 % KOH solutions, solid KOH) were added to the heat treatment process. Heat treatment experiments were performed under the nitrogen atmosphere at the temperature of 212 degrees C for 2 h. The MOR and chemical changes monitored by FT-IR spectra were then examined for the test groups. According to the results of this study, the use of commercial solid potassium hydroxide (KOH) in heat treatment decreased the degree of strength loss and mass loss of heat-treated wood. The strength (MOR) loss of samples heat-treated in the presence of potassium hydroxide was found to be only 5.4 %, while the strength loss in non-catalytic treatment was found to be 12.5 %.
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    Synthesis of biobased phenolic resins using catalytic pyrolysis oil and its effect on oriented strand board performance
    (Taylor & Francis Ltd, 2020) KOKTEN, Erkan Sami; Ozbay, Gunay; Ayrilmis, Nadir
    The aim of this work is to investigate the chemical, physical, thermal and mechanical properties of bio-oil-phenol-formaldehyde (BPF) resin synthesized with catalytic pyrolysis oil. In this way, catalysed and uncatalysed pyrolysis processes were carried out in a vacuum pyrolysis reactor at the temperature of 500 degrees C. Sodium hydroxide (NaOH) and potassium hydroxide (KOH) were used as catalysts in the catalysed pyrolysis processes. The BPF resins were synthesized using the bio-oil at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% phenol replacement levels. The chemical composition of the bio-oil was analyzed by GC/MS analysis. The thermal characteristics and chemical structures of the resins were characterized by TGA and FT-IR analysis, respectively. Physical properties including pH, viscosity, solid content and gel time of the resins were determined. Oriented Strand Board (OSB) were manufactured to evaluate the mechanical performances of modified resins. The BPF resins were successfully synthesized with phenol, bio-oil and formaldehyde. BPF resins synthesized with catalytic bio-oils showed better thermal stability than BPF resin synthesized with non-catalytic bio-oil. The mechanical test results showed that the IB strengths of OSBs made with BPF resins synthesized by use of NaOH exhibited better performance than OSBs commercial PF made.