A raw pine resin, which is a cheap, renewable and easily obtainable forest resource, was used to impregnate two different fast-growing solid woods (Eucalyptus grandis Hill Maiden and Pinus elliottii Engelm) and in situ polymerized to improve their hygroscopic, chemical, morphological, mechanical, and thermogravimetric properties. Biodegradation resistance against subterranean termites and white-rot fungus was also addressed. The treatment yielded changes in colorimetric properties, dimensional stability and surface hydrophobicity. Compared to its respective untreated wood, the treated pine one presented increases within 40-50 % in ASE, whereas the treated eucalyptus wood showed negative values around -15 % in this same comparison. Increases in MOE (70 %) and MOR (50 %) were obtained for the pine wood, whereas the same properties were unaffected for the eucalyptus wood. Thermal and biological properties of both woods were also positively affected. These results were associated with the solidified raw pine resin inside the wood structure, which was confirmed by infrared spectroscopy and SEM images, especially for the pine due to its large and long tracheids, as well as its lignin content and overall composition.

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Projeto acadêmico sem fins lucrativos desenvolvido no âmbito da iniciativa Acesso Aberto Caracterização da cor da madeira de clones...

O objetivo deste trabalho foi avaliar o efeito do tratamento térmico nas propriedades tecnológicas da madeira de Pinus elliottii. Para tanto, utilizou-se madeira de 22 anos, de onde foram obtidos corpos de prova com dimensões de 20 mm x 20 mm x 50 mm, os quais foram submetidos a tratamentos térmicos em três temperaturas distintas (160°C, 200°C e 240°C) por um período de tempo de 2 horas. Posteriormente, foram avaliadas a massa específica aparente, a perda de massa e a dureza Janka, seguindo as normas ASTM D 2395 (2017), ASTM D2017 (2005) e ASTM D143-94 (2014), respectivamente. Para a colorimetria, efetuaram-se quatro leituras em cada corpo de prova (2 no plano anatômico radial e 2 no tangencial) para obtenção dos parâmetros de claridade (L*), matriz vermelho (a*), matriz amarelo (b*), saturação da cor (c*), ângulo de tinta (h°) e variação total da cor (ΔE). Notou-se redução na massa específica aparente e perda de massa com o aumento da temperatura, justificado pela degradação dos componentes químicos de alto peso molecular. Em relação a dureza, observou-se aumento significativo para o tratamento a 160°C. Em relação a colorimetria, notou-se redução nos parâmetros de L*, b*, c* e h°, aumento nos parâmetros a* e (ΔE). Com isso, conclui-se que o tratamento térmico causa modificações nas propriedades físico-mecânicas e colorimétricas das madeiras de Pinus elliottii.

This study aims to compare the resistance against subterranean termites of wood–polymer composites produced by in situ polymerization. The biological tests were carried out by choice and no-choice feeding tests. Poly (furfuryl alcohol), poly(styrene) and poly (methyl methacrylate) were studied here. They were impregnated into a Brazilian fast-growing pine wood using a vacuum:pressure method and then cured under simple heating. These treatments were evaluated using chemical (by infrared spectroscopy) and morphological (by scanning electron microscopy) analyses. The termite attack was evaluated by mass loss determination and photography. In general, all the treatments were effective in protecting the fast-growing pine wood. Results obtained by no-choice tests indicated that the treatment solution with 75% of furfuryl alcohol was less effective than the others, which indicates that both choice and no-choice tests may be important in a comprehensive study on the termites resistance of solid woods.