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Organosilanes in wood protection – chemical analysis of wood and cellulose treated with MTMOS

Babicka Marta, Woźniak Magdalena, Ratajczak Izabela

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2020

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No. 110

5--8

EN

Organosilanes in wood protection – chemical analysis of wood and cellulose treated with MTMOS. The paper presents the results of methyltrimethoxysilane (MTMOS) reactivity with Scots pine wood and cellulose. The lignocellulosic material after treatment with ethanolic solution of MTMOS was analysed using instrumental methods – atomic absorption spectrometry (AAS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The analysis of silicon concentration in treated material indicated the presence of silane in structure of wood and cellulose. The bands characteristic of vibrations of the silicon-carbon and silicon-oxygen originating from MTMOS molecule were observed in the spectra of modified materials, which confirmed the reactivity of silane with wood and cellulose. Moreover, the chemical analysis indicated that MTMOS exhibited higher reactivity to cellulose than to pine wood.

PL

Organosilany w ochronie drewna – analizy chemiczne drewna i celulozy traktowanej MTMOS. W pracy przedstawiono wyniki badań reaktywności metylotrimetoksysilanu (MTMOS) z drewnem sosny zwyczajnej oraz celulozą. Materiał lignocelulozowy po działaniu etanolowego roztworu MTMOS był analizowany z wykorzystaniem metod instrumentalnych – AAS oraz ATR-FTIR. Analiza stężenia krzemu w impregnowanym materiale wskazuje na obecność silanu w strukturze drewna i celulozy. Charakterystyczne pasma dla drgań krzem-węgiel oraz krzem-tlen, pochodzące z cząsteczki MTMOS obserwowane w widmach modyfikowanych materiałów potwierdzają reaktywność silanu z drewnem oraz celulozą. Ponadto, analiza chemiczna wykazała, że MTMOS wykazywał wyższą reaktywność wobec celulozy niż drewna sosny.

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Waterlogged archaeological wood silanization with MTMOS

Siuda Joanna, Mazela Bartłomiej, Perdoch Waldemar

Drewno : prace naukowe, doniesienia, komunikaty

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2019

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vol. 62, nr 203

169--179

EN

A wooden object that has survived in a wet environment is characterised by water saturation and is called waterlogged wood. The subject of the study was elm piles, dating back to the 10th and11th century, excavated from Lednica lake archaeological site. Wooden piles showed a high degree of degradation. This was evidenced by their spongy and fragile structure. As a result of the biotic and abiotic degradation of the wood cell wall, a significant change in its chemical composition was observed. The weakening of the wood structure and its increase in porosity were as a result of cellulose degradation. The archaeological wood conservation method used until now is polyethylene glycol (PEG). However, this method has some drawbacks such as highdensity wood after treatment, the colour of the wood and it is a long-term process. It has already been found that alkoxysilanes are potential alternatives to the commonly used PEG. The purpose of the study was to determine the optimum concentration of methyltrimethoxysilane (MTMOS) for the medieval elm wood conservation. The general aim of the study was to develop an effective waterlogged wood dimensional stabilization through its silanization with MTMOS. After long-term dehydration (replacement of water for ethanol, during an ethanol bath) wood samples were saturated with MTMOS solutions of various concentrations. Wood samples were treated through the oscillating vacuum-pressure method. Dimensional stabilization of the sililated wood was estimated through the anti-shrink efficiency (ASE) calculation. The ASE value for PEG and MTMOS treated wood samples was 88.6% and 96.8% respectively. It was found that an ethanol solution of 20% MTMOS is the optimum concentration for waterlogged elm wood dimensional stabilization treatment (ASE = 94.1 %). The other advantage of this method includes a short impregnation time and low density of the preserved wood.

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Thermal decomposition of silica-methyltrimethoxysilane hybrid glasses studied by mass spectrometry

Nocuń M., Gajerski R., Siwulski S.

Optica Applicata

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2005

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Vol. 35, nr 4

901-906

EN

Organically modified silicates (hybrid glasses) have attracted much attention in recent years because they are considered to be promising materials with easy tailorable new properties. The structure of hybrid glass is a silica network with incorporated organic particles or chains. A sol-gel process is a convenient method for preparing bulk glasses, as well as films and layers. The main advantage of the sol-gel technique is high homogeneity and purity of synthesised material. The sol-gel is the only method giving possibility to introduce organic molecules into the inorganic network on the molecular level. Incorporated organic molecules influence mechanical, optical and thermal properties of the silica network. Series of glasses with different amount of methyltrimethoxysilane have been prepared and characterised. Thermal decomposition of methyl modified silica hybrid glasses have been studied by DTA, FTIR and mass spectrometry.