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This paper is an overview of our recent investigations of liquefied wood (LW) for preparation and application of wood adhesives and wood surface finishes. For the purpose of wood bonding, poplar wood (Populus nigra L.) was liquefied with ethylene glycol (EG) and sulphuric acid. The process of the curing of LW at different conditions was characterized using differential scanning calorimetry (DSC). The effect of the press temperature and the pressing time on the shear strength of bonds was monitored after the bonding of 5mm thick beech (Fagus sylvatica L.) lamellas. According to the results of DSC measurements, the curing process of the LW took place in two phases. In the initial physical phase the removal of water and EG from the LW occurred. This phase was followed by an exothermic chemical reaction. It was found that the optimum conditions for bonding beech lamellas were: a ratio between poplar and EG of 1:1, a press temperature of 180°C, and a pressing time of 12 minutes. Using such conditions it was possible to obtain bonds with a dry shear strength of about 7N/mm². For preparation of polyurethane wood coatings, poplar wood was liquefied with diethylene glycol (DEG) and the excessive DEG was removed from the reaction mixture prior to curing with isocyanate type hardener. For the purpose of preparation of light-coloured polyurethane coatings from bleached liquefied wood, liquefaction of wood was conducted with a mixture of polyethylene glycol (PEG) and glycerol (GLY) at a 9:1 ratio. Both LW based PU coatings and bleached LW based PU finishes were in the most relevant properties comparable to commercial polyurethane wood coatings. [ABSTRACT FROM AUTHOR]

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Copyright of Wood Industry / Drvna Industrija is the property of Drvna Industrija and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The number of commercial products claiming self-cleaning properties is rising and testing of long-term activity and durability of such coatings needs to be addressed more. The time-dependent changes of different characteristics like haze, transparency, and color are essential for transparent glazing materials. Herein, we aimed to examine whether the laboratory results obtained on the Zr-modified-titania-silica (TiZr) self-cleaning materials would translate to larger-scale outdoor-exposed testing. TiZr thin films were deposited via spraying onto float glass window surfaces and exposed into three different environments for 20 months. For comparison, a commercially available active SGG BIOCLEANTM glass and standard float glass were simultaneously exposed in the same conditions. It was shown that the self-cleaning property of either a commercial product or TiZr-coated float glass was not considerably effective in real field test conditions, although the previous laboratory tests showed pronounced photocatalytic activity of TiZr thin films. The inclination angle; however, was shown to have a considerable effect on the self-cleaning ability of samples, as did the rain patterns during the testing period. On the other hand, the anti-fogging effect of our TiZr material was very well expressed in controlled laboratory conditions (measuring droplet formation time) as well as in the real outdoor environment. [ABSTRACT FROM AUTHOR]

The number of commercial products claiming self-cleaning properties is rising and testing of long-term activity and durability of such coatings needs to be addressed more. The time-dependent changes of different characteristics like haze, transparency, and color are essential for transparent glazing materials. Herein, we aimed to examine whether the laboratory results obtained on the Zr-modified-titania-silica (TiZr) self-cleaning materials would translate to larger-scale outdoor-exposed testing. TiZr thin films were deposited via spraying onto float glass window surfaces and exposed into three different environments for 20 months. For comparison, a commercially available active SGG BIOCLEAN TM glass and standard float glass were simultaneously exposed in the same conditions. It was shown that the self-cleaning property of either a commercial product or TiZr-coated float glass was not considerably effective in real field test conditions, although the previous laboratory tests showed pronounced photocatalytic activity of TiZr thin films. The inclination angle; however, was shown to have a considerable effect on the self-cleaning ability of samples, as did the rain patterns during the testing period. On the other hand, the anti-fogging effect of our TiZr material was very well expressed in controlled laboratory conditions (measuring droplet formation time) as well as in the real outdoor environment.