ABSTRACT Background: Boiling, steaming, and microwave radiation treatments were used for softening and then manufacturing curved samples using three Brazilian hardwoods. Solid wood samples from Carya illinoinensis, Luehea divaricata and Platanus x acerifolia were characterized for bending quality, bending defects, minimum radius of bending, spring-back and moisture content. Results: Among the studied woods, Carya illinoinensis wood was the most suitable to conform curved samples since 96.7% of these wood samples reached a perfect curved shape. On the other hand, Luehea divaricata wood presented the worst behaviour, which was marked by only 36.7% of samples achieving a perfect shape. In general, the studied hydrothermal treatments and exposure times induced similar softening behaviours. Conclusion: In this sense, microwave heating seems to be a good option when compared to the other pathways, since it is known that this method require low consumptions of both time and energy.

Abstract: Measuring the natural resistance of wood is fundamental for proper use. The natural durability of five tropical wood species was investigated by field decay testing during exposure for 360 days. Wood logs (length of 0,5 m; diameter of 8 cm - 12 cm) were used in this study. The mass loss and decay index were calculated and visual analysis during the exposure time was performed for all samples. The samples presented evidence of two different groups concerning natural durability. The species in the first group (Mimosa caesalpiniifolia, Mimosa ophthalmocentra, and Mimosa tenuiflora) showed the highest resistance to biodeterioration, better or similar performance compared to treated Eucalypts wood (as control). The other group (Aspidosperma pyrifolium and Cordia oncocalyx) had lower natural resistance in outdoor service, being more susceptible to decay. In general, the wood of the first group is indicated for outdoor uses that require medium or prolonged exposure, such as timber stakes and fence posts.

Abstract It was impregnated commercial titanium dioxide into Pinus elliottii wood, aiming to increase its durability against the attack of brown rot fungus Postia placenta and photodegradation caused by ultraviolet radiation. The samples were put under 8 bar pressure for 3 hours at different concentrations of TiO2 (0.5%, 0.25%, 0.124% and 0%-control). To evaluate the effect of the fungus on the wood, the test was carried out according to ASTM D2017-05 and UNE-EN 113:1996 with modifications. The photodegradation was performed by exposing a tangential section to ultraviolet radiation for 400 hours, and the colorimetric parameters were periodically evaluated. Statistically, the treatments with TiO2 did not differ among themselves, but were much lower than the control, showing the effectiveness of this product in protecting the wood against the attacks of degraders. As for the photodegradation, the treated wood remained practically unchanged, differently from the control that had a darkening accelerated mainly in the first 50 hours. With this information, it can be stated that TiO2 treated wood is able to hinder the fungus access to the cell wall, to inhibit its growth and to create a barrier that protects the polymers from photodegradation, increasing its durability and emerging as a potential alternative for wood treatment.

Resumen Se impregnó dióxido de titanio comercial en la madera de Pinus elliottii, con el objetivo de aumentar su durabilidad contra el ataque del hongo pardo de la Postia placenta y la fotodegradación causada por la radiación ultravioleta. Las muestras se pusieron a una presión de 8 bar durante 3 horas a diferentes concentraciones de TiO2 (0.5%, 0.25%, 0.124% y 0% de control). Para evaluar el efecto del hongo en la madera, la prueba se realizó de acuerdo con la norma ASTM D2017-05 y UNE-EN 113:1996 con modificaciones. La fotodegradación se realizó exponiendo una sección tangencial a radiación ultravioleta durante 400 horas, y los parámetros colorimétricos se evaluaron periódicamente. Estadísticamente, los tratamientos con TiO2 no diferían entre sí, pero eran mucho más bajos que el control, mostrando la efectividad de este producto en la protección de la madera contra los ataques de los degradadores. En cuanto a la fotodegradación, la madera tratada se mantuvo prácticamente sin cambios, a diferencia del control que tuvo un oscurecimiento acelerado principalmente en las primeras 50 horas. Con esta información, se puede afirmar que la madera tratada con TiO2 puede dificultar el acceso del hongo a la pared celular, inhibir su crecimiento y crear una barrera que protege a los polímeros de la fotodegradación, aumentando su durabilidad y emergiendo como una alternativa potencial para tratamiento de la madera.

Abstract: The aim of the present study is to subject Pinus elliottii wood specimens to TiO2-based modification in order to make them resistant to water and UV radiation. The microwave-assisted solvothermal method, which is little reported in the literature, was here in use for this purpose. The adopted methodology led to a 1 % mass gain; although it was a low value, it was enough to fully coat the surface of the wood with nanoparticles to the extent of changing its characteristics and turning it into a functional material. The nanoparticle distribution on the surface of the wood changed your natural topography by increasing the surface area and, consequently, increasing the contact angle of the modified wood (approximately 130°). The leaching test showed that the wood remained coated after it was immersed in water, as well as that it did not lose its water-repelling ability. This result demonstrates the stable interaction between the two materials, due to hydroxyl radicals found in them. The coating also protected the wood against UV radiation for 500 hours of intense exposure, besides preserving its initial color. The properties achieved through this simple and fast modification process provide an alternative to help to improve the performance of the herein investigated wood species, mainly for applications in environments subjected to high solar incidence and humidity.

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.

Abstract: In the present study, three juvenile hardwoods (namely sycamore, pecan and london plane) were treated by boiling, steaming and microwave. Trees from Platanus x acerifolia (sycamore), Carya illinoinensis (pecan) and Luehea divaricata (london plane) were selected in homogeneous forests located in southern Brazil. Each hydrothermal treatment was performed for 60 min. In general, the hydrothermal treatments caused a certain surface inactivation effect, which was marked by decreased surface roughness, increased hydrophobic character and darkened colour patterns. Also, both decreased stiffness and strength, as well as increased deflectibility were obtained. These mechanisms were attributed to degradation in fine segments from amorphous polysaccharides, leaching of some organic extractives and fragmentation of lignin, as indirectly indicated by infrared spectra.

Abstract: This study aimed to evaluate the variations in thermal and chemical characteristics of juvenile Eucalyptus grandis wood submitted to a deterioration test by Nasutitermes termites. For this purpose, a biodeterioration test with termites was conducted according to ASTM D 3345 (2008), in which, after the end of the period corresponding to the test (40 days), we evaluated the mass loss, chemical composition and thermal stability of the main components of the deteriorated wood samples and those belonging to the control group. We found that deterioration due to exposure of the samples to Nasutitermes sp. termites caused a mass loss of 66,88% for wood with a density at 12% moisture content of 412 kg/m3. The quantitative chemical composition showed a reduction in the contents of cellulose, hemicellulose and lignin. Analysis of the variations of the organic functional groups related to the chemical composition of the wood by Fourier Transform Infrared Spectroscopy and relative intensity of the spectral bands also showed reductions, demonstrating homogeneous deterioration of the main components of the deteriorated woods. The thermal stability showed an increase in deteriorated wood for most of the temperature ranges, mainly for those that corresponded to losses in moisture and volatiles (25 °C - 100 °C), hemicelluloses (240 °C - 300 °C), celluloses, and together with initial lignin degradation (310 °C to 400 °C), possibly due to the removal of cellulose and hemicellulose, as well as the deposition of substances expelled by the termites in the cell wall. From the results, we conclude that the termites do not have specificity regarding the chemical component and that the deterioration caused variations in the chemical composition of the wood, whereas the opposite was observed for thermal stability, which presented an increase in most of the temperatures ranges for the deteriorated woods compared to the control group.

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.

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 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.

RESUMO O interesse pela síntese de nanopartículas utilizando extratos vegetais vem crescendo nas últimas décadas, devido a não geração de resíduos de químicos tóxicos e condições mais brandas de síntese. O Brasil é um dos líderes em florestas plantadas, principalmente do gênero Eucalyptus, em razão disso o objetivo deste trabalho foi sintetizar nanopartículas de óxido de zinco utilizando extrato etanólico das folhas de Eucalyptus dunnii. As folhas foram secas e moídas para obtenção de pó, 10 g deste foram adicionadas em 100 mL de álcool etílico, a solução foi mantida em banho-maria a 80 ºC por 75 min, a solução foi filtrada para obtenção do extrato. Para a síntese utilizou-se 20 mL de extrato e 1,57 g de acetato de zinco, a solução foi mantida a 80 ºC sob agitação magnética vigorosa por 20 min, transcorrido o tempo foi realizado tratamento térmico em mufla a 500 ºC por 2h. As nanopartículas obtidas apresentaram característica cristalina e diâmetro médio de 32,24 nm. O espectro FTIR do extrato apresentou diversos picos relacionados a compostos redutores capazes de realizar a síntese, enquanto o espectro das nanopartículas demonstrou que mesmo após a calcinação, ainda se detecta a presença de compostos orgânicos que podem ser responsáveis pela estabilização das mesmas. Sendo assim, o extrato etanólico de E. dunnii possui capacidade redutora para realizar a síntese de nanopartículas cristalinas de óxido de zinco.

ABSTRACT The interest in the synthesis of nanoparticles using plant extracts has been growing in recent decades due to the non-generation of toxic chemical residues and bland synthesis conditions. Brazil is one of the leaders in planted forests, mainly of the genus Eucalyptus, because of this the objective of this work was to synthesize nanoparticles of zinc oxide using ethanolic extract of the leaves of Eucalyptus dunnii. The leaves were dried and ground to obtain powder, 10 g of this was added in 100 ml of ethyl alcohol, the solution was kept in a water bath at 80 °C for 75 min, the solution was filtered to obtain the extract. For the synthesis 20 mL of extract and 1.57 g of zinc acetate were used, the solution was maintained at 80 ºC under vigorous magnetic stirring for 20 min, after which the heat treatment was carried out in a muffle at 500 ºC for 2 h. The obtained nanoparticles presented crystalline characteristic and average diameter of 32,24 nm. The FTIR spectrum of the extract showed several peaks related to reducing compounds capable of performing the synthesis, while the spectrum of the nanoparticles showed that even after calcination, the presence of organic compounds that can be responsible for their stabilization is still detected. Thus, the ethanolic extract of E. dunnii has a reducing capacity to perform the synthesis of crystalline na-noparticles of zinc oxide.

RESUMO O Pinus elliottii Engelm. possui uma vasta possibilidade de aplicações, porém, apresenta características indesejáveis às quais podem ser atenuadas com a adoção dos tratamentos de termorretificação e a furfurilação. Assim, este trabalho analisou a influência que os tratamentos de furfurilição e termorretificação exerceram em propriedades tecnológicas da madeira de Pinus elliottii. Para tanto, confeccionaram-se corpos de prova com dimensões de 15 x 15 x 250 mm (tangencial, radial e longitudinal), distribuídos igualmente em 5 tratamentos: controle, furfurilação com carga de 25% de álcool furfurílico (T F25%) e termorretificação em diferentes temperaturas (T 180°C, T 200°C e T 220°C). Avaliaram-se a variação da massa (ΔM) segundo adaptação da norma ASTM D 2017 (2005), à massa específica aparente ao teor de umidade de 12% (ρ12%), os módulos de elasticidade (MOE) e ruptura (MOR) obtidos pelo ensaio de flexão estática conforme a norma ASTM D 143 (2014), e a variação colorimétrica da madeira em conformidade com as recomendações do sistema CIE-L*a*b*. Verificou-se que o tratamento com furfurol provocou: aumentos significativos na massa, ρ12%, MOR, e causou o escurecimento da madeira, não afetando significativamente o MOE, em 5% de probabilidade de erro. Os tratamentos de termorretificação afetaram significativamente a perda de massa, contudo a maior diferença foi observada no tratamento T 220°C, o qual acarretou redução significativa no MOR em relação ao grupo controle, destacando-se que tal tratamento deixou a madeira com coloração semelhante aquela adquirida pela madeira tratada com furfurol. Conclui-se que ambos os tratamentos causaram o escurecimento da madeira de Pinus elliottii agregando assim valor estético, sendo que o tratamento à base de furfurol, com carga de 25%, ocasionou melhora nas propriedades tecnológicas da madeira. Apesar dos tratamentos de termorretificação terem aumentado o MOE, geraram perda de massa significativa, principalmente nos tratamentos mais agressivos, comprometendo assim possíveis usos da madeira com finalidade estrutural.

ABSTRACT The Pinus elliottii Engelm. has a wide range of applications, but it has undesirable characteristics that can be attenuated with the adoption of thermal rectification and furfurylation treatments. Thus, this work analyzed the influence of two treatments of modification, furfurilatyon and thermal rectification, in technological properties of Pinus elliottii Engelm. wood. For this, samples with dimensions of 15 x 15 x 250 mm (tangential, radial and longitudinal) were prepared, distributed equally among 5 treatments: control, furfurylation with 25% loading of furfuryl alcohol (T F25 %) and thermortification at different temperatures (T 180 ° C, T 200 ° C and T 220 ° C). It were evaluated the mass loss (PM) according to ASTM D 2017 (2005), specific gravity at 12% moisture content (ρ12%), elastic modulus (MOE) and rupture (MOR) by performing the static bending test in accordance with ASTM D 143 (2014), and wood color variation in accordance with the CIE-L*a*b* system recommendations. It was verified that the treatment with furfurol caused: significant increases in the mass, ρ12%, MOR, and caused the wood darkening, not significantly affecting the MOE, in 5% probability of error. The thermal rectification treatments significantly affected the mass loss, however the highest difference was observed in the T 220 ° C treatment, which caused a significant reduction on MOR in relation to the control group, highlighting that such treatment left the wood with coloration similar to that obtained by wood treated with furfurol. It's concluded that both treatments caused darkening of Pinus elliottii wood, thus adding aesthetic value, being that the furfurol treatment with a 25% load caused an improvement on technological properties of wood. In spite of the thermal rectification treatments increased the MOE, they generated significant mass loss, mainly in the more aggressive treatments, thus compromising possible uses of the wood with structural purpose.

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.

Abstract: The objective of this work was to form a hydrophobic surface in a highly porous wood by coating and incorporating TiO2 micro/nano structures through the microwave-assisted solvotermal method, without need any pre- or post-modification of the wood substrate, using low temperatures and short times. The behavior and morphology of the TiO2-treated surfaces was characterized using scanning electron microscopy (SEM), while the elemental composition was determined via energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. The results indicated that the crystallization of the TiO2 anatase phase was efficient and fully coated the wood surface during the solvothermal process. The treated wood contained TiO2 particles agglomerate with an average diameter of 200 nm that also allowed to coat an abundant fraction of tracheids cell walls. When investigated through X-ray spectroscopy-mapping, the element titanium appeared abundantly throughout the wood. After TiO2 growth in wood through the microwave-assisted solvotermal method, a roughness at the micro/nano scales structures was created on the wood surface, originating an increase in the contact angle up to 137°, which characterizes the appearance of a hydrophobic surface. The TiO2-treated wood demonstrated 85% of water absorption after 400 h of immersion, while untreated wood reached 160%, suggesting that the microwave-assisted solvotermal process promotes a delay in the progression of water absorption. This feature can improve the dimensional stability of wood, contributing to the increase of its durability and applications.