IMPACTS OF BLEACHING CHEMICALS AND OUTDOOR EXPOSURE ON CHANGES IN THE COLOR OF SOME VARNISHED WOODS

This study was carried out to determine the changes of the surface color of Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis Lipsky) woods after exterior conditioning. First, the samples were bleached with 25% NaOH and 17.5% H2O2. Afterwards, they were varnished with polyurethane and synthetic varnishes, and then they were exposed to exterior conditions for 12 months. Tests for color differences and metric chroma were done according to the ASTM D-2244 standard. It was deduced that exposure to exterior conditions causes color differences in samples, while bleaching with the given solution reduces that effects, and reverts the surface color to that of the natural control specimens. However, bleached specimens exposed to 12 months exterior conditioning had more discoloration than those of natural control samples. In conclusion, if the wood materials will be exposed to outdoors after bleaching, finishing process should be applied to surfaces in order to prevent further color change

Piroliza jelove (Abies bornmülleriana Mattf.) piljevine: karakterizacija bioulja i biougljena

This paper describes the research of slow pyrolysis of firwood (Abies bornmülleriana Mattf.) sawdust by using fixed-bed reactor. The effect of temperature ranging between 350 and 600 °C on gas, liquid and solid products was examined. The maximum bio-oil yield of 45.9 % was obtained at the final pyrolysis temperature of 500 °C. The elemental analysis and heating value of bio-oil and bio-char were determined, and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques such as Gas Chromatography–Mass Spectrometry (GC/MS) and Proton Nuclear Magnetic Resonance (1H-NMR). The liquid product was mainly composed of phenolics, including 2-methoxy-phenol, 2-methyl-phenol, phenol, as well as aldeyhdes, acids, esters, alcohols and ketones. The chemical characterization has shown that the bio-oil obtained from residues of forestry production, such as firwood sawdust, can be used as an environmental feedstock, which is an ideal candidate for alternative fuels. Moreover the bio-char can be used as an energy source and active carbon.U radu je opisano istraživanje spore pirolize jelove (Abies bornmülleriana Mattf.) piljevine uz primjenu fiksnog reaktora. Analiziran je učinak temperature u rasponu od 350 do 600 °C na plinovite, tekuće i krute proizvode pirolize. Maksimalni prinos bioulja od 45,9 % dobiven je na konačnoj temperaturi pirolize od 500 °C. Napravljena je elementarna analiza i određena ogrjevna vrijednost bioulja i biougljena, a zatim je ispitan kemijski sastav bioulja uz pomoć kromatografskih i spektroskopskih tehnika kao što su plinska kromatografija i masena spektrometrija (GC/MS) te protonska nuklearna magnetska rezonancija (1H-NMR). Tekući proizvodi pirolize sastavljeni su uglavnom od fenola, uključujući 2-metoksi-fenol, 2-metil-fenol, fenol, kao i od aldehida, kiselina, estera, alkohola i ketona. Kemijska su svojstva pokazala da je bioulje dobiveno od ostataka proizvodnje u šumarstvu, poput jelove piljevine, raspoloživa sirovina iz okoliša koja je idealna za alternativna goriva. Osim toga, biougljen se može koristiti kao izvor energije i kao aktivni ugljen

Sinteza fenolne smole ojačane nanočesticama TiO2 i njezin utjecaj na gorivost lamelirane drvne građe (LVL)

In this study, phenol-formaldehyde (PF) resin has been modified with titanium dioxide nanoparticles (nano-TiO2) at a varying ratio from 0.05 wt.% to 1.5 wt.% to enhance the thermal properties and combustion performance of the resins. The effect of the nano-TiO2 modification on the properties (chemical or thermal) of the resins was determined by Fourier to transform infrared (FT-IR) and thermal analysis (TGA) techniques. In addition, the combustion performance of laminated veneer lumber (LVL) samples bonded with the PF resin modified with nano-TiO2 was tested. The result of the FT-IR analysis indicated that the modified PF resins had match peaks to the reference PF resin. These similarities of the peaks supported that the modified PF resins were successfully synthesise with phenol, formaldehyde, and nano-TiO2. The PF resins modified by nano-TiO2 demonstrated better thermal stability than the reference resin. The nano-TiO2 modified PF resin exhibited a favourable influence on the combustion characteristics of LVL. In consequence, PF resin modified with nano-TiO2 could be used as a combustion retardant adhesive in the wood industry.U ovom je istraživanju fenol-formaldehidna smola (PF) modificirana nanočesticama titanijeva dioksida (nano-TiO2) u različitim omjerima, od 0,05 tež.% do 1,5 tež.% kako bi se poboljšala njezina toplinska svojstva i svojstva gorivosti. Utjecaj modifikacije nanočesticama TiO2 na svojstva smola (kemijska i toplinska) određen je Fourierovom transformiranom infracrvenom spektroskopijom (FT-IR) i termogravimetrijskom analizom (TGA). Osim toga, ispitana je gorivost uzoraka lamelirane drvne građe (LVL) lijepljene PF smolom modificiranom nano-česticama TiO2. Rezultati FT-IR analize pokazali su da modificirane PF smole imaju jednake vrhove kao referentna PF smola. Te sličnosti vrhova potvrđuju da su modificirane PF smole uspješno sintetizirane s fenolom, formaldehidom i nanočesticama TiO2. PF smole modificirane nanočesticama TiO2 pokazale su bolju toplinsku stabilnost od referentne smole i povoljno su utjecale na gorivost LVL-a. Stoga zaključujemo da bi se PF smola modificirana nanočesticama TiO2 mogla upotrebljavati kao ljepilo za usporavanje gorenja u drvnoj industriji

Synthesis and characterization of green phenolic resin with olive oil mill wastewater

Olive oil mill wastewater (OMW), a by-product of the olive oil industry, each year is generated millions of tons all over Mediterranean countries. Uncontrolled disposal of the OMW leads to massive environmental problems including soil and water pollution. In this experimental study, the OMW was used to partly replace clean water for getting prepared formaldehyde solution. Then, phenol and formaldehyde solutions were synthesized under alkali conditions to obtain more green phenol–formaldehyde (PF) resin. The effect of the OMW substitution level on the chemical and thermal properties of PF resin was examined by the Fourier transform infrared (FT-IR) spectral and thermogravimetric (TGA) analysis, respectively. Moreover, the bonding strength of each PF resin was evaluated under dry and wet conditions. It was found that FT-IR measurements showed that the PF resin containing various amounts of the OMW had a chemical structure very similar to the PF resin. The thermogravimetric analysis demonstrated that the low‐molecular‐weight organics in the OMW had negatively affected the thermal stability of the modified PF resins. In addition, the wood samples bonded with the PF resin containing up to 30 wt% OMW met the minimum requirements of interior and exterior bonding performance according to standard EN 12765. The OMW could be replaced by clean water up to 30 wt% for the production of green phenolic resin

Sinteza bioulja s fenolformaldehidnim smolama u alkalnim uvjetima: fizička, kemijska i toplinska svojstva smola i svojstvo lijepljenog spoja

In the present study, bio-oil produced from vacuum pyrolysis of woody biomass has been investigated as a source of chemical feedstock. Bio-based resins were produced using the bio- oil with phenol substitutions ranging from 10 to 30 wt%. The conventional GC/MS analysis was carried out for the evaluation of the chemical composition of bio-oil. TGA, DSC and FT-IR analyses were used in order to characterize the bio-oil-phenol-formaldehyde (BPF) resins. The bonding quality of wood samples bonded with the BPF resins was investigated under different pre-treatment conditions. The highest shear strength was observed for the control samples bonded with the laboratory PF resin. As the amount of bio-oil was increased up to 30 wt%, the shear strength of the samples decreased from 12.08 to 11.76 N/mm2. The bonding performance was not negatively affected by the combination of bio-oil under dry conditions. According to TS EN 12765 standard, the relevant performance requirements for bonded samples under dry conditions must be at least 10 N/mm2. Relating to the standard, all samples bonded with BPF resins obtained the requirements for durability class C1. Under wet conditions, the bonding performance was negatively affected by the addition of bio-oil. However, the BPF resins fulfilled the durability requirements for C1, C2, and C3 specified in EN 12765 (2002).U radu je predstavljeno istraživanje mogućnosti upotrebe bioulja dobivenoga vakuumskom pirolizom drvne biomase kao izvora kemijske sirovine. Biosmole su dobivene zamjenom 10 – 30 % mase (ili težinskog udjela) fenola biouljima. Analiza kemijskog sastava bioulja provedena je GC/MS metodom. Za karakterizaciju biouljnih fenolformaldehidnih smola (BPF) primijenjene su TGA, DSC i FT-IR analiza. Kvaliteta spoja uzoraka drva slijepljenih BPF smolama ispitivana je pri različitim uvjetima predobrade. Najveća čvrstoća na smicanje postignuta je na kontrolnim uzorcima lijepljenim laboratorijskim PF smolama. S povećanjem udjela bioulja do 30 % mase (ili težinskog udjela), čvrstoća na smicanje smanjila se s 12,08 na 11,76 N/mm2. Prema normi TS EN 12765, čvrstoća na smicanje u suhim uvjetima treba biti najmanje 10 N/mm2. Kombinacija bioulja s fenolformaldehidnim smolama nije negativno utjecala na svojstva slijepljenog spoja u suhim uvjetima i svi uzorci lijepljeni BPF smolama zadovoljili su zahtjeve klase trajnosti C1. U vlažnim uvjetima dodatak bioulja negativno je utjecao na svojstva slijepljenog spoja. Međutim, BPF smole ispunile su zahtjeve trajnosti za klase C1, C2 i C3 propisane normom EN 12765 (2002)

Physical Characterization and Bonding Performance of Phenol-Formaldehyde/Waste Tyre Pyrolytic Oil Blend Adhesive

Several million tons of waste tyres are generated every year all over the world. Many researches have been conducted on the use of recycled tyre products in the industrial area including chemical feedstock. In this study, the bonding performance of commercial phenol-formaldehyde (PF) adhesive containing different amounts of waste tyre pyrolytic oil (10-40 wt%) was investigated. The chemical structure of the waste tyre pyrolytic oil was analysed using Fourier transform infrared spectroscopy (FT-IR). The effect of the substitution level of the tyres pyrolytic oil on the physical characteristics of the PF adhesive was determined. In addition, the shear strength of single lap-joint wood samples bonded with the blended PF adhesives was determined for indoor and outdoor conditions. It was found that the solid content of the blended PF adhesives decreased with increasing amount of the pyrolytic oil. The bonding performance of the wood samples bonded with the PF adhesives containing up to 20 wt% pyrolytic oil were about the same as that of commercial PF adhesive. Finally, pyrolytic oil could be partially blended with commercial PF adhesive

Odunsu biyokütleden vakum piroliz ile biyoyakıt üretimi

Woody biomass is an important resource that can be utilized to obtain liquid fuel. Bio-oil is an encouraging renewable energy source due to finite fossil resources. In this study, vacuum pyrolysis of oak wood (Quercus petraea L.) residue was performed in a fixed-bed reactor at a high-temperature of 500 °C. Bio-oil, derived from oak wood was examined by a series of chromatographic/spectroscopic methods including elemental composition, FT-IR, and GC/MS analysis to determine the chemical structure. All the results indicated that the bio-oil comprises a complex mixture of oxygen-containing aromatic compounds such as phenols, alcohols, ketones, aldehydes, organic acids, and benzenes. The major compounds were identified as phenol and phenol derivatives. Bio-oil, produced from woody biomass may be used as an alternative fuel or chemical feedstock in different industrial applications.Odunsu biyokütle, sıvı yakıt üretiminde kullanılabilecek önemli bir kaynaktır. Biyoyağ, sınırlı fosil kaynakları nedeniyle umut verici bir alternatif enerji kaynağıdır. Bu çalışmada, meşe ağacı (Quercus petraea L.) odun talaşı, 500 °C sıcaklıkta vakum atmosferi altında sabit yataklı reaktörde piroliz edilmiştir. Biyoyağın kimyasal yapısı Elementel, FT-IR ve GC/MS analizi gibi bazı kromatografik ve spektroskopik teknikler kullanılarak analiz edilmiştir. Tüm sonuçlar gösterdi ki, biyoyağın fenoller, alkoller, ketonlar, aldehitler, organik asitler ve benzenler gibi çok çeşitli aromatik bileşikler içerdiği belirlenmiştir. Baskın bileşikler fenol ve fenol türevleri olarak tanımlanmıştır. Odunsu biyokütleden üretilen biyoyağ, alternative yakıt olarak veya farklı endüstriyel uygulamalarda kimyasalların üretiminde kullanılabilir

Characterization and adhesive performance of Phenol-Formaldehyde resol resin reinforced with carbon nanotubes

Chemical, physical, thermal properties and bonding quality of phenol-formaldehyde resol resin (PF) synthesized with single-walled carbon nanotubes (SWCNTs) was evaluated at varying ratios from 1 wt% to 5 wt%. The effect of the SWCNTs addition on thermal and chemical properties of the PF resins was characterized by thermal gravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy, respectively. FT-IR analysis revealed that the peaks of the modified PF resol resins were similar to those of the reference (laboratory-produced) PF resol resin. These similarities indicated that the synthesis of the resins with phenol, formaldehyde, and carbon nano tubes was successful. The PF resins modified using SWCNTs demonstrated higher thermal stability than the reference PF resin. It was found that the bonding strength of the PF resin containing 3 wt% SWCNTs could reach 12.45 N/mm(2) in dry conditions and 7.57 N/mm(2) in wet conditions. The bonding test results demonstrated that the SWCNTs were able to improve the bonding performance of the resin under dry and/or wet conditions. This work presents an effective method to improve PF resins with SWCNTs reinforcement for use in the wood and/or polymer composite industries

Odunsu biyokütlenin pirolizi ile biyoyağ üretiminin modellenmesi: yapay sinir ağları yaklaşımı

Özbay, Günay ( Aksaray, Yazar )This study is dedicated to developing a reliable artificial neural network (ANN) model to model the pyrolysis liquid product (bio-oil). Some related parameters with the bio-oil yield such as the pyrolysis temperature, duration, catalyst type, catalyst ratio, particle size, proximate, and ultimate analysis of the biomass were tested. Due to the different characteristics of different biomass types and pyrolysis methods, only slow and intermediate pyrolysis data from woody biomass were used in modeling. The correlation coefficients (R) were 0.992, 0.933, and 0.951 for training, validation, and testing, respectively. In order to evaluate the predictability of the ANN model, the predicted results were compared with the experimental results that were not introduced before. The simulated data were in good agreement with the experimental results indicating the reliability of the developed model. The relative impact results revealed that the most important parameter that affects the bio-oil yield was catalyst type (11.4%)

Synthesis and characterization of resol type phenol-formaldehyde resin improved by SiO2-Np

*Özbay, Günay (Aksaray, Yazar ) *Özçifçi, Ayhan (Aksaray, Yazar )In this work, resol type phenol-formaldehyde (RPF) resin was modified with silicon dioxide nanoparticles (SiO2-Np). SiO2-Np was added at varying ratios from 1 to 4 wt.% to improve the bonding performance of the RPF resins. The physical characteristics of the nano-modified RPF (nano-RPF) resins were examined. The effects of modification were studied by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The results of FT-IR revealed that the nano-RPF resins were successfully produced by phenol, formaldehyde, and SiO2-Np. The nano-RPF resins demonstrated high thermal stability at temperatures above 500°C. The adhesive performance of the nano-RPF resins was investigated under dry and wet conditions. The nano-RPF resins indicated better adhesive performance than unmodified RPF resin. The RPF resin could be improved by SiO2-Np