Leaching of copper-ethanolamine based preservatives from wood

Baker-etanoilaminski zaščitni pripravki za les uspešno nadomeščajo klasične pripravke na osnovi bakra in kroma. V prispevku so opisani osnovni mehanizmi vezave, podrobneje pa je predstavljenih nekaj dejavnikov, ki vplivajo na izpiranje bakrovih učinkovin iz lesa. To so sestava in koncentracija pripravka, čas in temperatura vezave, uporabljena drevesna vrsta in postopek zaščite. Številni rezultati kažejo, da etanolamin bistveno izboljša vezavo bakrovih učinkovin v les, po drugi strani pa kasneje lahko povzroči tudi depolimerizacijo lesnih polioz, kar se kaže v intenzivnejšem izpiranju bakra iz lesa.Copper-ethanolamine based preservatives are successfully replacing classical copper-chromium based preservative solutions. In this paper, the proposed fixation mechanisms are described. Additionaly,basic facts that influence copper leaching from wood are elucidated: composition and concentration of solutions, time and temperature of fixation as well as wood species and treatment method used. The results show that addition of ethanolamine significiantly improves copper fixation, but can on the other hand cause depolymerisation of wood polymers, which results in increased leaching of copper

Wood Properties and Processing

Wood-based materials are CO2-neutral, renewable, and considered to be environmentally friendly. The huge variety of wood species and wood-based composites allows a wide scope of creative and esthetic alternatives to materials with higher environmental impacts during production, use and disposal. Quality of wood is influenced by the genetic and environmental factors. One of the emerging uses of wood are building and construction applications. Modern building and construction practices would not be possible without use of wood or wood-based composites. The use of composites enables using wood of lower quality for the production of materials with engineered properties for specific target applications. Even more, the utilization of such reinforcing particles as carbon nanotubes and nanocellulose enables development of a new generation of composites with even better properties. The positive aspect of decomposability of waste wood can turn into the opposite when wood or wood-based materials are exposed to weathering, moisture oscillations, different discolorations, and degrading organisms. Protective measures are therefore unavoidable for many outdoor applications. Resistance of wood against different aging factors is always a combined effect of toxic or inhibiting ingredients on the one hand, and of structural, anatomical, or chemical ways of excluding moisture on the other

Adsorption of coper-ethanolamine preservatives in wood

Baker-etanolaminski pripravki so trenutno ena izmed najpomembnejših skupin za zaščito lesa v tretjem in četrtem razredu izpostavitve. Kljub večletni komercialni uporabi celotni mehanizem vezave teh pripravkov v les še ni pojasnjen. Znano je, da se v les vežejo hitreje kot pripravki na osnovi bakra bakrovih in kromakromovih spojin. V literaturi pa še ni podatkov o tem, kdaj je ta reakcija končana in kateri dejavniki vplivajo nanjo. V prispevku je opisan vpliv časa impregnacije, lesne vrste (smrekovine in bukovine), temperature in koncentracije komercialnega baker-etanolaminskega zaščitnega pripravka Silvanolin na adsorpcijo bakra bakrovih spojin v lesne iveri. Vsebnost bakra v ivereh smo določali z rentgensko fluorescenčno spektroskopijo(XRF). Ugotovili smo, da je adsorpcija bakrovih učinkovin v les,impregniran z baker-etanolaminskimi pripravki, hiter proces. V prvih šestih urah impregnacije se adsorbira med 60 in 80 % navzetega bakra v les. Z višjo koncentracijo pripravka narašča tudi adsorpcija bakrovih učinkovin v iveri. Impregnacija pri 50 °C močno izboljša adsorpcijo bakrovih učinkovin v les.Copper-ethanolamine based preservatives are one of the most important wood preservatives for protection of wood in third and fourth use class. Despite the fact that they are commercially used for several years, complete mechanismof fixation in wood has been not resolved to date. It is clear that copper-ethanolamine system reacts with wood faster than copper-chromium based wood preservatives. It is not known, however, which parameters control this process of fixation and when it is finished. Influence of impregnation time, wood species (Norway spruce, beech), temperature and concentration of commercial copper-ethanolamine preservative solution Silvanolin on copper adsorption to wood particles is elucidated in this contribution. Concentrationof copper in wood particles was determined with X-ray fluorescence spectroscopy (XRF). The results confirmed that the reaction of copper-ethanolamine complexes in wood is a fast process. During the initial six hours of impregnation, between 60 and 80% of retained copper is adsorbed in wood. Copper adsorption is increasing with increasing concentration as well, and it can be significantly improved with impregnation at 50°C

Correlation between degradation of Beech wood and penetration of Pilodyn 6J needle

Ocenjevanje razkrojenosti lesa zaradi delovanja gliv bele trohnobe je pomembno za pravilno ukrepanje pri sanaciji lesenih izdelkov, še posebno nosilnih lesenih konstrukcij. Pilodyn je splošno uporabno orodje za vrednotenje gostote lesa številnih komercialnih lesnih vrst, zato nas je zanimalo, ali je primeren tudi za oceno razkrojenosti lesa. Meritve z napravo Pilodyn so bile opravljene na bukovini, ki je bila za različna časovna obdobja izpostavljena glivam bele trohnobe (Trametes versicolor, Hypoxylon fragiforme in Pleurotus ostreatus) v skladu s standardom SIST EN 113. Rezultati kažejo, da med izgubo mase zaradi delovanja gliv razkrojevalk in globino prodora igle Pilodyn obstaja povezava.Assessment of white rot decay is one of the most important issues for appropriate treatment of infested wooden commodities, particularly damaged constructions. Pilodyn is a well-established tool for assessing density of several commercially important plantation species, therefore we were interested in its suitability to evaluate the rate of decay as well. The Pilodyn measurements performed on common beech wood (Fagus sylvatica), exposedto three white rot fungi (Trametes versicolor, Hypoxylon fragiforme andPleurotus ostreatus) according to the modified EN 113 procedure, indicate correlations between Pilodyn needle penetration and mass loss

Infection of CCB preserved and leached wood specimens with wood decay fungi

Les, zaščiten s pripravki CCB, je odporen proti trohnjenju. Vendar v zadnjih letih opažamo, da se na lesu, impregniranem s CCB, pojavljajo okužbe z glivami, tolerantnimi na Cu. V raziskavi smo opazovali preraščanje in penetracijo hif na zaščitenih vzorcih, izpostavljenim glivam razkrojevalkam, in osvetlili vpliv izpiranja na kolonizacijo. Vzorce smo izdelali iz beljave smrekovine (Picea abies) in jih impregnirali s 5 % raztopino CCB v skladu s standardom SIST EN 113. Del kondicioniranih vzorcev smo izpirali po standardu SIST EN 84. V tretjino izpranih in neizpranih vzorcev smo vzdolžno zvrtali luknjo in vanjo vstavili palčko (r = 1,5 mm, l = 25 mm). Nato smo odprtino zatesnili z epoksidnim premazom. Sterilizirane impregnirane in neimpregnirane vzorce smo izpostavili dvema na baker tolerantnima sevoma (Antrodia vaillantii in Leucogyrophana pinastri) in dvema na baker občutljivima izolatoma (Poria monticola, Gloeophyllum trabeum). Po izpostavitvi smo iz vzorcev previdno odstranili palčko in jo postavili na sterilno hranilno gojišče, kjer smo dva tedna opazovali prisotnost hif. Stopnjo kolonizacije smo ovrednotili tudi z merjenjem CO2. Po 16 tednih izpostavitve smo ugotovili še izgubo mase izpostavljenih vzorcev. Neimpregnirane vzorce so najhitreje prerasle hife glive G. trabeum. Po drugi strani pa pri vzorcih, impregniranih s CCB, na palčkah tudi po 12 tednih izpostavitve nismo zasledili prisotnosti hif. Prodiranje hif pri izpranih impregniranih vzorcih je bilo bistveno hitrejše. Menimo, da je razlog za intenzivnejšo kolonizacijo izpranih vzorcev, impregniranih s CCB, izprani bor, ki v nižjih koncentracijah ni zaviral preraščanja micelija.CCB treated wood is generally resistant to all wood decay fungi. However, like at CCA impregnated wood, susceptibility of CCB treated wood to copper tolerant fungi have been observed. It was investigated whether the hyphae of brown rot fungi could overgrow on and penetrate into the wood samples. Samples made of Norway spruce (Picea abies) were impregnated with 5 % CCB solution according to the EN 113 procedure. After conditioning, part of the samples was leached according to the EN 84 method. A small stick of unimpregnated wood (r = 1.5 mm, l = 25 mm) was inserted into a hole, bored in the center of the sample, and then sealed with epoxy coating. Sterilized, leached and non-leached impregnated and unimpregnated specimens were exposed to two copper-tolerant (Antrodia vaillantii, Leucogyrophana pinastri) and two copper sensitive (Poria monticola, Gloeophyllum trabeum) brown rot fungal strains. After exposure, the inserted wood pieces were removed from the specimens and put onto nutrient medium in petri dishes. Growth of the hyphae from those wood pieces was then visually determined. Rate of colonization by the fungi was determined by measurement of CO2. Mass losses after 16 weeks of exposure were also determined. The fastest colonization of the unimpregnated specimens was by G. trabeum. On the other hand, no fungal growth could be detected on non-leached CCB impregnated specimens even after 12 weeks of exposure. However, significantly more intense colonization by the copper tolerant fungi was detected on the leached CCB treated samples. We concluded that the reason for observed higher susceptibility originates in leached boron, which did not influence, in lower concentrations, fungal growth

Impregnability and leachability of copper based preservatives with regard to anatomical plane of wood

Zaradi omejitev uporabe klasičnih baker/kromovih pripravkov, industrija išče alternative za zaščito lesa v stiku z zemljo. Za impregnacijo takšnega lesa moramo uporabiti fungicide, ki se iz lesa ne izpirajo. Učinkovitost vezave v les določamo s standardno metodo, z majhnimi vzorci, kjer je delež aksialnih površin večji kot v praksi. Namen prispevka je ugotoviti, kakšno je izpiranje bakrovih učinkovin iz različnih anatomskih smeri. V ta namen smo orientirane smrekove vzorce impregnirali s pomočjo vakuuma z dvema bakrovima pripravkomavodno raztopino bakrovega(II) sulfata in komercialnim pripravkom Silvanolin. Rezultati so pokazali, da je izpiranje iz radialnih in tangencialnih površin primerljivo. Ugotovili smo, da se modra galica pri višjih koncentracijah najbolj izpira iz aksialnih ploskev, Silvanolin pa iz radialnih in tangencialnih površin.Due to the limited use of classical copper/chromium based preservatives, the industry seeks for alternatives for preservation of wood in ground applications. For such purposes, fungicides fixed in wood are utilised. For estimation of fixation, standard method that prescribes small specimens with higher portion of axial surfaces than in practice is utilised. The purpose of this article is to determine copper leaching from different anatomical planes.Orientated Norway spruce wood blocks were impregnated with aqueous solution of copper(II) sulphate and commercial preservative Silvanolin. The results showed comparable leaching from radial and tangential surfaces. However, more prominent leaching of copper(II) sulphate at higher concentrations and less extensive leaching of Silvanolin from axial surfaces was established

Influence of selected environmental factors on moisture dynamics of beech wood

Beech is one of the most important tree species in Slovenia. Unfortunately, there is much more beech wood incremented annually than consumed. Thus, it is of great importance to develop new applications for use of beech wood. One of the possible solutions is use of beech in outdoor applications. However, if beech is used outdoor it has to be somehow protected. In the recent period, non-biocidal methods of wood protection such as thermal modification and use of wax emulsions are gaining more and more importance, hence we applied these two methods to beech wood in present research as well. During the research, water exclusion efficacy of wood was determined. Wood was subjected to various abiotic and biotic degradation protocols. The results exhibited that the best water performance was achieved in wax treated thermally modified beech. Water performance of wax treated wood was not affected by abiotic and biotic degradation factors. By contrast, the aging protocols applied considerably reduced water exclusion efficacy of beech and thermally modified beech wood