Abstract: This study aims to evaluate chemical characteristics, antioxidant and antibacterial activities of organic compounds extracted from three Eucalyptus wood and Corymbia maculate wood using ethanol as a solvent. To obtain the ethanolic extracts, 15 g of a powdered wood sample was mixed with 150 mL of ethyl alcohol 99 % PA by constant mechanical stirring, which was further magnetically mixed at 60 ºC for 24 h. The extractives were analyzed utilizing percent yield, Fourier-transform infrared spectrum, inhibitory index (measured after antimicrobial tests), antioxidant activity, and condensed tannins content. The Eucalyptus dunnii extract showed the highest percent yield. The infrared spectra of all the extractives presented similar profiles, with remarkable bands ascribed to the presence of lipophilic extracts, sterols, fatty acids, and other hydroxylated substances, such as carbohydrates and phenolic compounds. In all cases, the higher the concentration of the extractive was, the higher the antioxidant activity was. The antioxidant activity of Eucalyptus saligna extract stood out since overcame that of the positive control (ascorbic acid). Regarding the condensed tannins content, that extract from Eucalyptus grandis excelled.

RESUMO Este estudo tem como objetivo, avaliações e correlações entre propriedades físicas da madeira, sendo estas, massa especifica básica, teor de umidade, absorção de água, perda de massa em 50°C e 100°C, contração linear máximo (β), coeficiente de anisotropia de contração (Ca β), inchamento linear máximo (α) e coeficiente de anisotropia de inchamento (Ca α), sendo analisado para as madeiras das seguintes espécies: Corymbia citriodora, Corymbia maculata, Eucalyptus dunnii, Eucalyptus grandis, Eucalyptus saligna e Eucalyptus tereticornis. Para isso, foram confeccionados corpos de prova de 20 mm x 20 mm x 15 mm. Para as análises físicas, os corpos de prova foram submersos em água até a saturação, condicionados sob temperatura de 20°C com umidade relativa (UR) de 65% e secos em estufa (100 ± 3°C). Foram coletados dados de massa e dimensões desses corpos de prova em cada uma dessas etapas, para posterior cálculo das propriedades tecnológicas. Observou-se que as madeiras das sete espécies apresentaram diferença significativa. Analisando-se as propriedades de perda de massa a 100°C e massa específica básica, como também, anisotropia para inchamento (Ca α) e contração (Ca β), apresentam uma correlação significativa, sendo diretamente proporcional. A massa específica básica e absorção de água, perda de massa a 100°C e absorção de água, Coeficiente de Anisotropia de Contração (Ca β) e absorção de água, apresentaram correlações significativas, sendo essas propriedades inversamente proporcionais. As madeiras do gênero Corymbia apresentaram valores médios de propriedades tecnológicas, superiores às do gênero Eucalyptus, destacando a madeira Corymbia citriodora.

ABSTRACT This study aims at assessing and correlating physical properties of wood, such as basic specific mass, moisture content, water absorption, loss of mass at 50 ° C and 100 ° C, maximum linear contraction (β), coefficient of contraction anisotropy (Ca β), maximum linear swelling (α) and coefficient of swelling anisotropy (Caα), being analyzed for wood of the following species: Corymbia citriodora, Corymbia maculata, Eucalyptus dunnii, Eucalyptus grandis, Eucalyptus saligna and Eucalyptus tereticornis. For that, 20 mm x 20 mm x 15 mm specimens were prepared. For the physical analyzes, the specimens were submerged in water until saturated, conditioned at a temperature of 20 ° C with relative humidity (RH) of 65% and oven dried (100 ± 3 ° C). Mass data and dimensions of these specimens were collected in each of these stages, for later calculation of the technological properties. It was observed that the wood of the seven species presented significant difference. Analyzing the mass loss properties at 100 ° C and basic specific mass, as well as anisotropy for swelling (Ca α) and contraction (Caβ), they present a significant correlation, being directly proportional. The basic specific mass and water absorption, loss of mass at 100 ° C and water absorption, Coefficient of Contraction Anisotropy (Caβ) and water absorption, showed significant correlations, being these inversely proportional properties. The wood of the genus Corymbia presented average values of technological properties superior to those of the genus Eucalyptus, highlighting the wood Corymbia citriodora.

RESUMO As madeiras apresentam propriedades tecnológicas distintas, por ser material orgânico e heterogêneo, sendo necessário uma avaliação para o uso adequado. Sendo assim, o objetivo deste trabalho foi a avaliação de propriedades tecnológicas, sendo elas: massa especifica básica, massa especifica aparente a 12%, teor de umidade de equilíbrio, flexão estática (MOE e MOR), compressão paralela as fibras (Fc e Ec), análise colorimétrica, termogravimetria (TGA e DTG) e fourier transform infrared spectroscopy (FT-IR), das espécies de Corymbia maculata, Eucalyptus grandis, Pinus elliottii. Determinaram-se as propriedades tecnológicas conforme descrito nas normas ASTM D 2395-17 (2017) e ASTM D 143-94 (2014). Em relação as propriedades físico-mecânicas, as species apresentaram diferenças significativas baseadas em análises estatisticas, possuindo destaque a espécie de Corymbia maculata. Em relação a análise colorimétrica, foi verificado que a espécie Corymbia maculata possui uma coloração marrom-avermelhado, a espécie de Pinus elliottii amarelo com tonalidade clara, enquanto o Eucalyptus grandis avermelhada com tonalidade clara. Para o FT-IR foi constatado picos semelhantes entre as espécies, porém com intensidades distintas, sendo estes referentes as vibrações moleculares características dos componentes orgânicos da madeira. Por meio da análise termogravimétrica percebe-se que as espécies de Pinus elliottii e Corymbia maculata, apresentaram maior estabilidade térmica, quando comparadas ao Eucalyptus grandis, possuindo um menor percentual de perda de massa e um retardo de temperatura em relação ao pico máximo de degradação (DTG), próximo aos 400°C, sendo essas propriedades analisadas com testes ANOVA com significância de 5%. Sendo assim destaca-se uma heterogeneidade entre as espécies avaliadas nesse estudo, tanto do ponto de vista físico, mecânico, térmico e químico, fazendo-se necessário a caracterização de tais propriedades para o emprego correto destes materiais.

ABSTRACT The woods have distinct technological properties, as they are organic and heterogeneous material, requiring an assessment for proper use. Therefore, the objective of this work was the evaluation of technological properties, which are: basic density, apparent density at 12%, equilibrium moisture content, static flexion (MOE and MOR), parallel compression of the fibers (Fc and Ec), colorimetric analysis, thermogravimetry (TGA and DTG) and Fourier transform infrared spectroscopy (FT-IR), of the species of Corymbia maculata, Eucalyptus grandis, Pinus elliottii. The technological properties were determined as described in the ASTM D 2395-17 (2017) and ASTM D 143-94 (2014) standards. Regarding the physical-mechanical properties, the species showed significant differences based on statistical analysis, highlighting the species of Corymbia maculata. Regarding the colorimetric analysis, it was found that the species Corymbia maculata has a reddish-brown color, the Pinus elliottii species loves it with a light shade, while the Eucalyptus grandis reddish with a light shade. For FT-IR, similar peaks were found between species, but with different intensities, these being related to the molecular vibrations characteristic of the organic components of wood. Through thermogravimetric analysis, it can be seen that the species of Pinus elliottii and Corymbia maculata, presented greater thermal stability when compared to Eucalyptus grandis, having a lower percentage of mass loss and a delay in temperature in relation to the maximum peak of degradation ( DTG), close to 400 ° C, and these properties were analyzed with ANOVA tests with 5% significance. Thus, there is a heterogeneity among the species evaluated in this study, both from a physical, mechanical, thermal and chemical point of view, making it necessary to characterize these properties for the correct use of these materials.

Abstract: Organic substances have been used for different wood treatments, especially impregnation procedures, aiming at improve certain wood properties. The objective of this study was to evaluate dimensional stability and colourimetric features for a mature pine wood (Pinus elliottii) impregnated by vacuum-pressure process with variable concentrations (10 wt%, 25 wt% and 50 wt%) of furfuryl alcohol and using ethyl alcohol as catalyst. The wood samples were characterized for:linear shrinkages, linear swellings, shrinkage anisotropy, swelling anisotropy, as well as colorimetric parameters (following the CIELab method). The impregnation with furfuryl alcohol increased the dimensional stability of the studied pine wood and the treatment with a concentration of 50 wt% stood out based on these results. Regarding the colourpatterns, there were changes in the final colorimetric appearances of the treated wood samples, which acquired darker and reddish colours when compared to the pristine group. The treatment with 50 wt% of furfuryl alcohol also was responsible for the highest colour change and, because of that, may be indicated for solid wood products with high added value.

RESUMO As madeiras de Pinus apresentam características indesejáveis às quais podem ser atenuadas com a aplicação de tratamentos, no qual é destacado a furfurilação. Sendo assim, o objetivo deste trabalho foi avaliar o efeito da impregnação de álcool furfurílico nas propriedades físicas e mecânicas da madeira de Pinus elliottii. Para tanto, foram utilizados 4 tratamentos: controle e com diferentes cargas de álcool furfurílico (10%, 25% e 50%). Determinaram-se às propriedades tecnológicas conforme descrito nas normas ASTM D 2395-17 (2017) e ASTM D 143-94 (2014). Verificou-se que para as propriedades mecânicas, a resistência à compressão paralela às fibras, em que o parâmetro MOE teve um acréscimo significativo para todos os tratamentos em relação ao grupo controle, em destaque especial para o tratamento (TF25%), para o MOR obteve-se valores superiores, porém sem diferenças significativas. Em relação a dureza Janka, a tensão máxima no plano anatômico transversal, constatou-se valores superiores se comparados ao controle, com destaque o tratamento (TF50%), o qual demonstrou maiores valores com diferença significativa. Para o plano tangencial não foram constatadas diferenças significativas, se mantendo praticamente constantes os valores médios entre os tratamentos e o controle. Para flexão estática, MOR e MOE, não se observaram diferenças significativas, sendo essas propriedades analisadas com testes ANOVA com significância de 5%. Com isso pode-se concluir que a impregnação com álcool furfurílico foi eficaz, devido às melhorias de desempenho mecânico observado. Visto o potencial da furfurilação empregada na madeira com base nestes resultados, sugere-se mais pesquisar neste campo de modo a fomentar maiores informações sobre a utilização deste tratamento em madeira.

ABSTRACT Pinus wood presents undesirable characteristics that can be attenuated with the application of treatments, in which the furfurylation is highlighted. Therefore, the objective of this work was to evaluate the effect of impregnation of furfuryl alcohol on the physical and mechanical properties of Pinus elliottii wood. For this, 4 treatments were used: control and with different loads of furfuryl alcohol (10%, 25% and 50%). The properties were determined as described in ASTM D 2395-17 (2017) and ASTM D 143-94 (2014). It was verified that, for the mechanical properties, the compression resistance parallel to the fibers, in which the MOE parameter had a significant increase for all the treatments in relation to the control group, especially for treatment (TF25%), for the MOR, higher values were obtained, but without significant differences. Regarding Janka hardness, the maximum tension in the transverse anatomical plane, higher values were observed when compared to the control, with emphasis on treatment (TF50%), which showed higher values with significant difference. For the tangential plane, no significant differences were observed, maintaining the average values between the treatments and the control practically constant. For static flexion, MOR and MOE, no significant differences were observed, these properties being analyzed with ANOVA tests with significance of 5%. With this it can be concluded that the impregnation with furfuryl alcohol was effective, due to improvements in mechanical de-performance observed. Considering the potential of furfurylation employed in wood based on these results, it is suggested to do more research in this field in order to promote more information on the use of this wood treatment.