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Waterlogged archaeological wood silanization with MTMOS

Siuda Joanna, Mazela Bartłomiej, Perdoch Waldemar

Drewno : prace naukowe, doniesienia, komunikaty

2019

vol. 62, nr 203

169--179

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.

The influence of surface modification of wood particles with carbon nanotubes on properties of particleboard glued with phenol-formaldehyde resin

Łukawski Damian, Grześkowiak Wojciech, Dukarska Dorota, Mazela Bartłomiej, Lekawa-Raus Agnieszka, Dudkowiak Alina

Drewno : prace naukowe, doniesienia, komunikaty

2019

vol. 62, nr 203

93--105

Research was carried out on a newly manufactured particleboard (PB) containing carbon nanotubes (CNTs) to determine the effect of the CNTs on physical, mechanical and combustion properties of the board. The experiment consisted of two stages. In the first, wood particles were treated with an aqueous suspension of CNTs (0.2% w/w) and sodium dodecylbenzenesulfonate (0.2% w/w) as a dispersant. After drying to constant weight, a modified form of the ASTM E69 method was used to determine the effectiveness of fire protection provided by CNT-modified wood chips. The rate of wood decomposition decreased significantly, and the time to complete combustion increased from 18 to 22.5 min for the reference and CNT-modified wood particles respectively. In the second stage of the experiment a particleboard bonded with phenyl-formaldehyde resin was produced, in which the particles were modified with CNTs using the method described in the first stage. Selected physical and mechanical properties of the final board were determined. Samples of the board were tested using a mass loss calorimeter in accordance with the ISO 13927 standard, and mechanical tests were performed by applicable standard methods. However, no significant improvement in the properties of the PB were observed.