Bioresource Technology , , A novel approach for the liquefaction of wood powder: usage of pyrolytic bio-oil as a reaction medium. International Journal of Energy Research , 40 14 , Kinetic and product composition study on the cellulose liquefaction in polyhydric alcohols. Depolymerization of lignins and their applications for the preparation of polyols and rigid polyurethane foams: A review.
Renewable and Sustainable Energy Reviews , 60 , Production of biomaterials from cork: Liquefaction in polyhydric alcohols at moderate temperatures. Industrial Crops and Products , 54 , European Journal of Wood and Wood Products , 70 , Synthesis and properties of resol-type phenol-formaldehyde resins prepared from H2SO4- and HCl-catalyzed phenol-liquefied Cryptomeria japonica wood. Use of biocrude derived from woody biomass to substitute phenol at a high-substitution level for the production of biobased phenolic resol resins.
Journal of Applied Polymer Science , 5 , The preparation and application of a new formaldehyde-free adhesive for plywood. International Journal of Adhesion and Adhesives , 31 6 , Synthesis of polymers from organic solvent liquefied biomass: A review. Renewable and Sustainable Energy Reviews , 15 7 , Synthesis of phenolic resol resins using cornstalk-derived bio-oil produced by direct liquefaction in hot-compressed phenol—water. Journal of Industrial and Engineering Chemistry , 15 6 , Industrial Crops and Products , 30 1 , Phenol-formaldehyde-type resins made from phenol-liquefied wood for the bonding of particleboard.
Journal of Applied Polymer Science , 3 , Polymer-Plastics Technology and Engineering , 48 1 , Effendi , H. Gerhauser , A.
Production of renewable phenolic resins by thermochemical conversion of biomass: A review. The cumulative growth was measured from the third day of inoculation. The measurements of fungal growth in three directions gave us the average fungal mycelia growth per day.
Fungi on pure PDA overgrew Petri dishes in 10 days, and this is why fungal growth reduction was observed on the 10 th day. Nevertheless, some other interesting results were exhibited also during all 13 days of exposing to fungi. Liquefaction of CCB containing black poplar wood. Both elements in UBP sawdust were under detection limit of the X-ray fluorescence spectrometer. Table 1. Determination of the optimal liquefaction conditions of uncontaminated black poplar sawdust was studied by Budija et al.
They used diethylene glycol DEG as a reagent and sulphuric acid as a catalyst. Further increasing of the ratio did not have influence on LY. Figure 1.
Differences in LY were observable only in the first stages of liquefaction, where a higher amount of EG was needed to achieve uniform mixing of EG with the sawdust. The same was observed by Budija et al. In the last stage of liquefaction, the influence of the ratio between EG and LRIBP sawdust was not exhibited anymore, as the sawdust was immersed long enough to be completely wetted and presumably impregnated with the reaction mixture.
Figure 2. There were significant differences observed in the initial stages of the liquefaction reaction. Namely, it is well known, that CCB impregnated wood is less hydrophilic than uncontaminated wood Maldas and Kamdem This was clearly evident at our experiment as well. In addition, it was presumed that the presence of metal ions in the system will catalyse the process, but as can be resolved from Figure 3 , increased concentrations of copper and chromium did not result in increased LY.
Figure 3. The most important reason is the dilution during the liquefaction process, since the ratio between sawdust and EG was 1: 3. Additionally, during liquefaction some volatile products that evaporate from the mixture during liquefaction are formed Budija et al.
Formation of such compounds cannot be excluded also in our case. Elucidation of the mass balance of the heavy metals should be the topic of future investigations. Table 2. Concentration of copper and chromium in. Although the main focus of the present article is on Cu and Cr in liquefied wood, one may be interested in what happens with the boron containing compounds during liquefaction of CCB containing sawdust and could they also have any role in a potential fungal inhibition.
On the basis of the data from literature, three assumptions can be made: i volatile complexes of boron with wood polymer fragments and other compounds in liquefied wood could be formed. Because of the high temperature applied during the liquefaction reaction, the majority of boron could evaporate from the mixture; ii various complexes with organic compounds in liquefied wood could be formed; iii some part of boron could be eliminated by evaporation of volatile complexes and the other part could remain in the liquefaction product in the form of stable complexes.
For instance, some borate esters which could certainly be formed with some depolymerised fragments of wood components are well known to be volatile. Even more, such complexes are well known to be applied as wood preservatives e.
Baysal and Yalinkilic It is also known that dehydration of boric acid under heat yields some forms of boric oxide depending on temperature level, and on the other hand, boric acid itself can be vaporised under heat.
Similarly, as written by Kataoka et al. Especially in acidic media such as liquefied wood in our experiment the volatilities are extremely increased. Secondly, various boron containing complexes for the purpose of wood protection are mentioned in the review by Obanda et al. Just as an example, spiro-borate complexes of derivatised 2-hydroxybenzyl alcohol may react with Cu II to form the tetrakis boronato bis aquo copper II.
Penn et al. Borate is also known to form stable complexes with cis-diols Landers et al. As stated by Asad et al. All in all, the mentioned examples support well enough our presumptions mentioned under i - iii , but certainly they should be elucidated and potentially confirmed by additional extensive research of boron complexes in liquefied wood.
Fungicidal properties of liquefied sawdust. The ratio between EG and sawdust was 1: 3. Although these were not the optimal conditions in the first stages of liquefaction Figure 1 , they were used to minimize the influence of non-reacted EG in liquefied sawdust on fungicidal properties. The higher ratio between EG and sawdust does not have the influence on LY in the last stage of liquefaction Figure 1. The fungal cultures were grown and maintained on PDA because we wanted to draw attention just to the influence of liquefied sawdust on chosen fungi and to avoid potential interactions between wood and liquefied wood.
Table 3. Some interesting results in table 3 are compared further and more clearly shown in figures Figure 4. The same was observed at Antrodia vaillantii Figure 5 , although the observed growth reduction was not as pronounced as at Trametes versicolor. Figure 5. The lowest growth reduction was observed at Gloeophyllum trabeum Figure 6.
So, it seems that copper and chromium did not reduce the growth but even promoted it, when compared to the effect of UBP liquefied sawdust containing samples. One may assume that the observed growth reduction at the LRIBP and HRIBP liquefied sawdust samples was the consequence of the liquefied sawdust itself, only, especially when its pH is taken into consideration. The minimum inhibitory concentration of copper for Trametes versicolor is ppm and for Gloeophyllum trabeum ppm Humar and Lesar The minimum inhibitory concentration of copper for Antrodia vaillantii is ppm in nutrient medium Pohleven et al.
This concentration of copper is much lower than the inhibitory concentration for any of our test fungi. Figure 6. Figure 7. Influence of different concentrations of UBP liquefied sawdust on growth reduction of Trametes versicolor. On the other hand, Humar et al. In the last days Trametes versicolor started to grow.
Figure 8. Various studies showed that copper is biocidally inactive in small quantities. It is incorporated into a large number of plant organic compounds. Would it liquefy, or what? There may be some odd high pressure and temperature configuration where wood will liquefy, but not at normal pressures. Water or plastics can liquefy at high temps because the bonds between the molecules break down before the bonds within them, so the individual molecules are then free to slide past one another.
Wood is a complex polymer with all sorts of crosslinkings. By the time it gets hot enough to break those crosslinkings and allow the molecules to move relative to one another a lot of the internal bonds will have been ruptured by the heat.
Wood is made up mostly of cellulose and lignin, both of which are long-chain polymers of simpler molecules. My SWAG is that the bonds between the units of the polymers would disintegrate first, so that the wood would become converted to a powder instead of a liquid.
Wood can be considered a fiber reinforced polymer, where lignin is the polymer and cellulose is the fiber. There are also hemicelluloes in there, but in smaller amounts, and which contribute less to the strength of the composite.
Some wood pulps are made using thermo mechanical or semichemical processes that use heat and mechanical energy to soften and remove the lignin. The thing with lignin is that is is an amorphous molecule of very high molecular weight, and has no defined melting point.
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