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Summary Aspen wood (Populus tremula) as sawdust was chemically modified through a two-step procedure: esterification with maleic anhydride and subsequent oligoesterification with glycidyl methacrylate and maleic anhydride. Simplified techniques consisting of impregnation by immersion followed by thermal treatment using conventional or microwave heating were employed. Chemical analyses and infra-red spectroscopy showed some differences in the chemical composition and structure of the resulting oligoesterified wood depending on the synthesis technique. However, the thermoplastic properties, clearly revealed by thermomechanical analysis, were quite similar and comparable to those exhibited by the oligoesterified wood resulting via classical synthesis. Moreover, similar degrees of chemical modification were obtained for a significantly shorter duration of the process when microwave heating was employed instead of conventional heating.

Summary Aspen wood (Populus tremula) as sawdust was chemically modified through a two-step procedure: esterification with maleic anhydride and subsequent oligoesterification with glycidyl methacrylate and maleic anhydride. Chemical analyses and infra-red spectroscopy revealed the differences in the chemical composition and structure of wood as a result of this treatment. These changes were also reflected by a hygroscopicity test and thermal analyses such as thermogravimetry and thermomechanical analysis. The esterified wood showed an increased hygroscopicity and a decreased thermal stability compared to unmodified wood. In contrast, the oligoesterified wood demonstrated a reduced hygroscopicity and a comparable thermal stability up to about 200°C. The thermomechanical analysis of oligoesterified wood clearly showed a significant softening phenomenon in the range 80–140°C, a direct evidence of the thermoplastic properties gained by this chemical modification.

Color and chemical changes were investigated in beech wood (Fagus sylvatica L.) following light steaming and further heat treatment for 2.5 h at 200 °C by two techniques (industrial ThermoWood versus a laboratory procedure in the presence of air). Colour changes were evaluated in the CIE Lab system, while Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR) investigation was employed to highlight and compare the associated chemical changes. Light steaming caused only minor chemical changes (limited hydrolysis of hemicelluloses) not ready detectable by FTIR. In contrast, heat treatments caused visible changes in the FTIR spectra, especially in the region 1800 to 1500 cm . A significant variation of the ratios of relevant absorption bands indicated complex chemical changes, including hydrolytic, oxidative, and condensation reactions. FTIR ratios and the mass loss values in the two heat treatments relate, both indicating a more advanced modification in the case of the ThermoWood process.

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Consolidation of frail, degraded wood is a key issue of wooden cultural heritage conservation. Paraloid B72 is one of the most often used consolidant in conservation practice. The present research aimed at formulating stable consolidation solutions of Paraloid B72 with ZnO nano-additives and at determining the influence of these additives on the penetration pathways, retention of the consolidation material into wood and on the water behavior of the treated wood. The experiments were performed on sound samples of aspen (Populus tremula). The addition of nano-ZnO slightly increased the uptake and retention of the consolidant within the wooden structure and led to hydrophobic surfaces. However, the influence of nano-ZnO additives to the water absorption was not conclusive. Scanning Electron Microscope coupled with an EDX Detector investigation proved vessels, fibers, and interconnecting pits as main pathways of consolidant penetration into the wooden structure as well as the presence and distribution of nano-ZnO.