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The objective of this work was to evaluate whether the chemical composition of wood and its crystallinity can help in the analysis of degradation by fungi and insects in logs of Amazonian wood species stored in a stockyard. For this study, wood from five commercial species that had been stored in an open yard for six months was used. The scale of degradation by fungi and insects, the moisture content of the logs, the total extractive content, lignin, holocellulose and the crystallinity were evaluated. It was concluded that the position of the logs in the stacks, associated with the storage time, influenced the evaluated characteristics. It was also observed that X-ray diffraction has potential for analysis of the degradation by fungi and insects in logs of Amazonian species stored in the stockyard. [ABSTRACT FROM AUTHOR]

Thermal modification mechanisms and their effects on physical and mechanical properties of native Amazon hardwoods are not yet completely understood. It is expected that such treatments can improve the properties of low-value Amazonian woods and sapwood residues. This study aimed to investigate the impact of heat treatment on the swelling and mechanical properties (strength and stiffness to Static Bending and Janka hardness) of tauari wood (Couratari spp.), a low-value Amazonian hardwood. For this, tauari wood samples were thermally modified in an electric oven under hot air irradiation at final temperatures of 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, and 210 °C for 2.5 h. The main results showed that thermal modification increased the hydrophobicity of tauari wood without any noticeable effects on the mechanical behavior of the wood up to 200 °C. It was stated that up to 200 °C thermal modification is beneficial in terms of gains in hydrophobicity. In contrast, above 200 °C, despite an increase in hydrophobicity, consistent decreases in strength (MOR) and hardness were observed. [ABSTRACT FROM AUTHOR]

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