ABSTRACT Lignin, the second most abundant biopolymer on the planet, has properties that can be widely explored, moving from waste to products with high added value. Therefore, this work aimed to extract and characterize Klason and Kraft lignins from sawdust and black liquor, considered industrial waste. The raw material used was Eucalyptus grandis chips. To obtain Klason lignin according to TAPPI 222 om-02 (2002), part of the chips were transformed into sawdust. To obtain Kraft lignin, another part of the chips passed through a digester to obtain black liquor, which was subsequently subjected to acid precipitation. The characterization of lignins was performed by granulometry analysis, scanning electron microscopy with elemental chemical analysis (EDS), transmission electron microscopy, medium infrared spectroscopy, thermogravimetric analysis and differential calorimetry. Microscopy analyzes showed irregular structures of various shapes, including spherical structures, most evident and frequent in Kraft lignin. The elementary chemical analysis showed that the lignin washing process was satisfactory, due to the small percentage of sulfur detected in the samples. The results of the granulometry confirmed that the lignins had micrometric dimensions. The medium infrared spectra showed the characteristic peaks of the chemical composition of lignin. The thermal analysis showed three ranges of degradation, attributed to the drying of the samples, degradation of the hemicelluloses and the lignin itself. All results confirmed the obtaining of Klason and Kraft lignins. Therefore, the techniques were satisfactory in transforming waste into lignin with the potential for a variety of commercial applications, mainly in the chemical and pharmaceutical industries.

RESUMO A lignina, o segundo biopolímero mais abundante do planeta, possui propriedades que podem ser amplamente exploradas, passando de resíduos a produtos de alto valor agregado. Portanto, este trabalho teve como objetivo extrair e caracterizar as ligninas Klason e Kraft de serragem e licor negro, considerados resíduos industriais. A matéria-prima utilizada foram cavacos de Eucalyptus grandis. Para a obtenção da lignina Klason conforme TAPPI 222 om-02 (2002), parte dos cavacos foi transformada em serragem. Para a obtenção da lignina Kraft, outra parte dos cavacos passou por um digestor para a obtenção do licor negro, que posteriormente foi submetido à precipitação ácida. A caracterização das ligninas foi realizada por análise de granulometria, microscopia eletrônica de varredura com análise química elementar (EDS), microscopia eletrônica de transmissão, espectroscopia de infravermelho médio, análise termogravimétrica e calorimetria diferencial. As análises microscópicas mostraram estruturas irregulares de vários formatos, incluindo estruturas esféricas, mais evidentes e frequentes na lignina Kraft. A análise química elementar mostrou que o processo de lavagem da lignina foi satisfatório, devido ao pequeno percentual de enxofre detectado nas amostras. Os resultados da granulometria confirmaram que as ligninas apresentaram dimensões micrométricas. Os espectros de infravermelho médio mostraram os picos característicos da composição química da lignina. A análise térmica mostrou três faixas de degradação, atribuídas à secagem das amostras, degradação das hemiceluloses e da própria lignina. Todos os resultados confirmaram a obtenção das ligninas Klason e Kraft. Portanto, as técnicas foram satisfatórias na transformação de resíduos em lignina com potencial para diversas aplicações comerciais, principalmente nas indústrias química e farmacêutica.

Abstract: The wood is exposed to possible damages caused by weather, requiring the application of a finishing coat to provide extra protection. The aim of this work was to evaluate the influence of the addition of microfibrillated cellulose in waterborne varnish on the colorimetric parameters, wettability and finish characteristics of wood products. Color was evaluated with a CM-5 spectrophotometer; surface wettability was analyzed by contact angle measurement using a drop shape analysis goniometer; and abrasion, adhesion and impact tests were performed to evaluate the quality of the coating. The coating’s optical characteristics were not affected by the addition of microfibrillated cellulose. The changes in wood wettability were small, with no statistical difference between the wood treated with plain varnish and that with unbleached microfibrillated cellulose. In the analysis of the variation of the contact angle during the elapsed time, the coating containing unbleached microfibrillated cellulose presented the best results. The results of finish quality did not show numerical changes after the addition of the microfibrillated cellulose, but qualitatively the microfibrillated cellulose caused better anchoring of the coating to the specimens. Therefore, the use of microfibrillated cellulose as reinforcement in coatings has potential, but tests with different consistencies and tests of other properties are necessary.

Abstract: Because of the need for identification of forest species, especially for detection of illegal wood trade, the objective of this study was to evaluate the potential of colorimetry for differentiation of Inga vera Willd., Muellera campestris (Mart. ex Benth.) M.J. Silva & A.M.G. Azevedo and Machaerium paraguariense Hassl., species of the Fabaceae family, native to the Araucaria Forest in the state of Santa Catarina, southern Brazil. Discs at breast height were collected from three trees of each species and the colorimetric parameters (L*, a*, b*, C* and h) and visible spectra were evaluated in different radial position of the trunk (near bark, intermediate and near pith) and three different anatomical sections (transversal, radial and tangential surfaces). Mean values of hue angle (h) among the colorimetric parameters resulted in the highest potential for species discrimination. With respect to radial trunk position and anatomical section, parameters a* (green-red) and h were not statistically different, independent of the wood samples evaluated. For other parameters (L*, b* and C*), each species presented distinct results. Principal component analysis with second derivative of visible spectra discriminated all species. Colorimetry associated with chemometrics allowed to distinguish I. vera, M. campestris and M. paraguariense.

Abstract The aim of this study was to verify the potential of the colorimetric technique in the identification of some species marketed as “tauari” in the Brazilian Amazon. CIE L* a* b* parameters were applied to determine the colour of 35 wood samples from the main wood poles of the State of Para, Brazil, and the scientific collections of the Museu Paraense Emilio Goeldi (Walter A. Egler Collection) and Embrapa Amazônia Oriental. From each sample, data were obtained in the three wood surfaces: transversal, longitudinal tangential and longitudinal radial. The coordinate b*, which showed the yellow pigment, exerted greater weight in the color characterization of the 35 samples marketed as tauari, being more evident in the tangential and radial sections. In PCA, MGW wood samples showed considerably distinct color patterns in relation to PA and IAN samples, and the h and L* parameters provided better informations for distinguishing species from sample sources. The colorimetric technique can be used as an auxiliary tool in the identification of wood. However, the simultaneous use of colorimetry with the anatomical description of wood is suggested, given the complexity of the species-level separation in “tauari” group.

Resumen: En el presente trabajo se determinaron los parámetros colorimétricos mediante el sistema CIELAB y la densidad aparente por densitometría de rayos X en madera de Guazuma crinita para obtener información de su calidad en el uso como madera solida o transformada. La evaluación se realizó en tres niveles del eje axial (basal, medio y apical) de una plantación de 5 y 8 años, en la zona de Puerto Inca, departamento de Huánuco, Perú. En ambas edades, empleando el sistema CIElab, se encontró que la madera es de coloración homogénea y se clasifica como rosa grisáceo. La densidad aparente medida por densitometría de rayos X en el sentido médula - corteza fue de 520 kg/m3 y 560 kg/m3 para 5 y 8 años respectivamente; con promedios mayores en el nivel basal (5 años: 650 kg/m3; 8 años:680 kg/m3) y menores en el nivel apical (5 años: 430 kg/m3; 8 años: 470 kg/m3). Los perfiles densitométricos mostraron, en general, que radialmente hay un aumento de la densidad aparente en el sentido médula - corteza. La densidad de la madera madera de 5 años resultó más uniforme que la de 8 años con un índice de uniformidad de 149,7 y 170,3, respectivamente.

Abstract: In the present work, the colorimetric parameters were determined using the CIELAB system and the apparent density by X-ray densitometry in Guazuma crinita Mart. wood to obtain information of its quality in use as solid or transformed wood. The evaluation was carried out in three levels of the axial axis (base, medium, apical) of one plantation of 5 and 8 years old, in Puerto Inca, department of Huánuco, Peru. It was found that in both ages, according to CIElab system, the wood is of homogeneous coloration and is classified as greyish pink. The apparent density measured by X ray densitometry in the pith - bark direction was found to be 520 kg/m3 and 560 kg/m3 for 5 and 8 years, respectively; with higher values at the basal level (5 years old: 650 kg/m3; 8 years old: 680 kg/m3) and lower towards the apical part (5 years old: 430 kg/m3; 8 years old: 470 kg/m3). The densitometric profiles showed, in general, that there is an increase in apparent density radially in the pith-bark direction. The 5-year-old wood density was more uniform than the 8-year-old one with a uniformity index of 149,7 and 170,3, respectively.

Resumo O objetivo deste estudo foi avaliar as características de cor em amostras de madeira de Acacia mangium de uma plantação homogênea no estado da Bahia, nordeste do Brasil, e também analisar a influência da secção anatômica e posição radial do tronco na resposta de cor para contribuir com informações para o melhor aproveitamento da madeira, como por exemplo, a otimização do rendimento das peças em serraria através da forma estética mais aceitável pelo consumidor final. Foram cortadas seis árvores com idade de 14 anos. A espécie foi identificada por análise anatômica no Laboratório de Anatomia da madeira da Universidade Federal do Paraná, comparando a amostra coletada com o material autenticado. Um disco da base de cada árvore foi dividido em seis amostras orientadas em cortes anatômicos (transversal, radial e tangencial), com dimensões de 20 × 20 × 30 mm, próximo a medula, região intermediária e região próxima a casca. Foram avaliadas um total de 36 amostras, 12 de cada posição. A avaliação colorimétrica foi realizada com um espectrofotômetro CM-5. Foram obtidos dados sobre a luminosidade, coordenadas cromáticas verde-vermelho e azul-amarelo e foram calculados valores de saturação e ângulo de tonalidade. A madeira de Acacia de floresta plantada é classificada como cor de azeitona. Os parâmetros de cor foram influenciados pela secção anatômica e posição radial no tronco, sendo observado valores de luminosidade de 44 para a seção transversal, 55 para a tangencial e 57 para a radial. As secções transversais tinham valores mais baixos em comparação com as superfícies longitudinais e as secções radiais tinham maior luminosidade do que as secções tangenciais. A região próxima da casca apresentava valores mais baixos na maioria dos parâmetros colorimétricos, exceto o ângulo de tonalidade, em comparação com as regiões intermédias e próximas da medula, o qual está em torno de 70 para todas as posições na madeira.

Abstract The aim of this study was to evaluate color characteristics in wood samples from Acacia mangium from a homogeneous plantation in Bahia state, northeast Brazil, and also analyze the influence of anatomical section and radial position in the trunk on color response to contribute to information for the best use of the wood, such as, for example, the optimization of the performance of the pieces in sawmill through the most acceptable aesthetic form by the final consumer. Six trees with age of 14 years were cut. The species was identified by anatomical analysis at the Laboratory of Wood Anatomy of the Federal University of Paraná, comparing the sample collected with the authenticated material. A disc from the base of each tree was divided into six samples oriented in anatomical sections (transversal, radial and tangential), with dimensions of 20 × 20 × 30mm, named near pith, intermediate and near bark. A total of 36 samples were evaluated, 12 from each position. The colorimetric evaluation was performed with a CM-5 spectrophotometer. Data on lightness, green-red and blue-yellow chromatic coordinates were obtained, and values of saturation and hue angle were calculated. Acacia wood from planted forest is classified as olive color. Color parameters were influenced by anatomical section and radial position in the trunk, being found 44 for the transversal section, 55 for the tangential section and 57 in the radial for luminosity. Transversal sections had lower values in comparison to longitudinal surfaces and radial sections had higher luminosity than tangential sections. The near bark region presented lower values in most colorimetric parameters, except hue angle, in comparison with the intermediate and near pith regions, which was around 70 in the different positions of the wood.

Abstract: The search for new technologies to improve adhesives and the properties of reconstituted wood panels is constant, and nanotechnology is a tool for this purpose. The aim of this study is investigating the effect of adding nanocellulose in the formulation of the adhesive phenol-formaldehyde on the physico-mechanical properties of Pinus taeda plywood panels. Three ratios of nanofibrillated cellulose (NFC) were added to the adhesive formulation used to produce plywood panels: 0,026 %; 0,038 % or 0,064 %. The panels were tested according to the European standards; apparent density, resistance to parallel and perpendicular flexure and glue line shear strength were determined after 6 hours of boiling and after the boiling cycle for the 1st glue line (face) and 2nd glue line (core). The use of NFC in the adhesive caused an increase of viscosity and reduction of the gel time of the adhesive. The apparent density of the panels was not influenced by the addition of NFC, but the properties of parallel bending, perpendicular flexing and glue line shear were sensitive to the addition of NFC. The NR2 treatment (0,038 % NFC) presented the best results in the mechanical tests.

Abstract: Thermal modification is a treatment that seeks to improve the properties of wood and reduce the heterogeneity in its color. The objective of this work was to evaluate the effect of thermal treatment on the anatomical, chemical, physical, mechanical, colorimetric, and thermal stability properties of teakwood. For this, teakwood samples were treated by an industrial autoclave at final cycle temperature of 160 ºC. The reduction of cell wall thickness, the formation of cross-fissures and the crystallization of the wax inside the pores were observed in the anatomical structure. Chemically, the extractives evaporated and the polysaccharides ruptured, of which hemicellulose was the most affected. The heat treatment promoted lower equilibrium moisture, reducing the hygroscopicity and improving the dimensional stability of the wood. Considering the mechanical properties, the rupture modulus and the longitudinal and tangential hardness decreased after the heat treatment. The color of the wood changed significantly, from pink to dark brown. The treated wood had higher thermal stability, with greater weight loss at higher temperatures than the untreated wood.

SUMMARY: The aim of this study was to measure and compare some anatomical elements of wood and charcoal of Inga vera, Machaerium paraguariense and Muellera campestris to support identification of the materials seized by regulatory authorities. For each species, three trees were analyzed. After wood evaluation, all samples (moisture content of 12 ± 1 %) were wrapped in aluminum foil and carbonized in a muffle furnace for 8 hours with final temperature of 450 °C and a heating rate of 1.66 °C/min. The number of measurements was based on 30 readings regarding tangential diameter and vessel density, along with frequency, height and width of rays (in micrometers). After carbonization, changes in cell dimensions and different behavior were observed in the Fabaceae species evaluated. In all species, vessel diameter declined; vessel density decreased in Inga vera and increased in the other species; ray height decreased in Inga vera and Muellera campestris, and increased in Machaerium paraguariense; and ray width and frequency increased in all species. We concluded that due to the conservation of wood anatomical structures after carbonization, the inclusion of this species in a database would be effective to support efforts to control deforestation in the south of Brazil.

RESUMEN: El objetivo de este estudio fue medir y comparar algunos elementos anatómicos de madera y carbón vegetal de Inga vera, Machaerium paraguariense y Muellera campestris con el fin de apoyar la identificación de los materiales incautados por las autoridades reguladoras. Para cada especie, se analizaron tres árboles. Después de la evaluación de la madera, todas las muestras (contenido de humedad de 12 ± 1 %) se envolvieron en papel de aluminio y se carbonizaron en un horno de mufla durante 8 horas con una temperatura final de 450 °C y una velocidad de calentamiento de 1,66 °C/min. El número de mediciones se basó en 30 lecturas con respecto al diámetro tangencial y densidad de los vasos, junto con frecuencia, altura y ancho de los radios (en micrómetros). Después de la carbonización, se observaron cambios en las dimensiones celulares y diferentes comportamientos en las especies de Fabaceae evaluadas. En todas las especies, el diámetro del vaso disminuyó; la frecuencia de los vasos disminuyó en Inga vera y aumentó en otras especies; la altura de los radios disminuyó en Inga vera y Muellera campestris, y aumentó en Machaerium paraguariense; y el ancho y la frecuencia de los radios aumentaron en todas las especies. Concluimos que debido a la conservación de las estructuras anatómicas de la madera después de la carbonización, la inclusión de esta especie en una base de datos sería efectiva para apoyar los esfuerzos para controlar la deforestación en el sur de Brasil.

ABSTRACT In this study, based on the mechanical shear treatment, the cellulosic pulp was fibrillated in nanofibrils dispersed in aqueous suspension. Nanofibrillated Cellulose (NFC) matrix - Polyvinyl Alcohol (PVA) nanocomposite films’ were prepared by casting from NFC/PVA suspension mixtures. The thermal and mechanical properties of the obtained films were evaluated. Low levels (2, 5 and 10 wt%) of PVA were used as an additive in a nanofibrillated cellulose (NFC) matrix. The predominant use of NFC, with superior properties due to its purity, with an efficient and environmentally friendly method, has allowed the production of NFC-based biodegradable materials with enhanced properties for high-level applications. The addition of PVA to the NFC matrix produced positive results, as it causes little aesthetic interference, without changes in surface brightness. After the addition of PVA the films showed a great gain in mechanical strength, increasing by 24% in Young’s modulus with the addition of 10% PVA. Even after addition, the samples’ chemical composition remains unchanged and the mixture shows a decrease in the film surface hydrophilicity when compared to pure NFC. Composite material thermal analysis indicates that thermal degradation temperatures remain unchanged after the addition of PVA. Although PVA is not very temperature resistant, in the proportions used, NFC thermal resistance is preserved.

Abstract This study evaluated color and reflectance spectra during industrial process of yerba mate leaves and tested the potential of these parameters to predict moisture and tannin content, to be applied as an auxiliary tool in quality control in industry. Two groups of yerba mate samples were evaluated: one grown under organic and another under conventional conditions. The results indicate an increase in lightness, loss of the green color, although less marked in the organic samples, an increase of yellow in both types of samples along processing due to moisture removal at high temperatures. For moisture content, reflectance curve can be applied with R2 ≥ 0.9, and for tannin content the sum of b* parameter and spectra in region 590-700 nm are recommended. Color parameters and reflectance spectra can be applied for a preliminary evaluation of moisture and tannin content in the yerba mate industry, contributing for the quality control of samples.

Abstract: The aim of the present study was to determine the physical properties of the Guazuma crinita wood by conventional methods, as well as to estimate these properties by near infrared spectroscopy (NIR) through the development of multivariate calibration models. The samples were obtained from five trees and from three levels longitudinally for 5 and 8 years of age randomly selected from a plantation in Puerto Inca, Department of Huánuco (Perú). Basic density, volumetric, tangential and radial contraction were determined by the conventional methods. Models were developed by regression of partial least squares (PLS) through mathematical transformations. For the validation of the models, a new group of samples -which did not participate in the development of the model were used. Statistical significance was found F 5años = 191,5; F 8 años =84,9) between the different heights in the stem. Basic density and volumetric contraction show values of (0,88 and 0,83) and RPDp (1,55 and 3,27) acceptable for prediction.

Resumen: El objetivo del presente estudio fue determinar las propiedades físicas de la madera de Guazuma crinita por el método convencional, así como estimar estas propiedades por espectroscopia infrarroja cercana (NIR) a través del desarrollo de modelos de calibración multivariada. Las muestras fueron obtenidas de tres niveles del eje longitudinal en 5 árboles para 5 y 8 años de edad seleccionados al azar de una plantación en la zona de Puerto Inca, departamento de Huánuco (Perú). Se determinó la densidad básica, contracción total volumétrica, tangencial y radial por el método destructivo o convencional. Los modelos fueron desarrollados por regresión de mínimos cuadrados parciales (PLS) mediante transformaciones matemáticas. Para la validación de los modelos se empleó un grupo de muestras que no participo en el desarrollo del modelo. Se encontró diferencias estadísticas significativas (F 5años = 191,5; F 8años =84,9) entre las tres alturas en el fuste. Para densidad básica y contracción volumétrica se encontró valores de (0,88 y 0,83) y RPDp (1,55 y 3,27) aceptables para la predicción.

ABSTRACT Wood color and properties are variables among and within species, and fast and non-destructive techniques can be applied to their characterization, being also important in wood marketing and quality control. This paper evaluated the influence of age on the discrimination of Tectona grandis L.F. (teak) wood by VIS/NIR spectroscopy. Wood from three ages, with heartwood and sapwood, were studied, totaling 36 samples per age. Quantitative colorimetric data, based on CIELAB 1976, visible and NIR infrared spectra were collected from radial and tangential surfaces in five positions of each sample, in a total of 540 spectra. Both techniques were adequate for age discrimination in teak wood. Statistical differences were observed in the chromatic coordinates in heartwood and sapwood for each age. VIS/NIR spectroscopy can be applied for age discrimination based on teak solid samples and for wood quality control.

RESUMO Este trabalho investiga as propriedades físicas e mecânicas de filmes nanoestruturados produzidos a partir da polpa kraft branqueada de Pinus sp. Para obter a nanocelulose, a polpa kraft branqueada foi submetida a seis diferentes intensidades de desfibrilação pelo moinho: dois, cinco, dez, 20, 30 e 40 passes. A influência do número de passes foi avaliada por meio das propriedades físicas e mecânicas dos filmes. Os resultados indicam que a presença de nanofibrilas reduziu a espessura e aumentou consideravelmente os valores de densidade dos filmes fabricados. Observou-se aumento da resistência à tração de 300% e o índice de ruptura foi dez vezes maior em relação aos papéis normais. A estrutura mais compacta e a menor porosidade causada pela maior superfície de contato entre as nanofibrilas nos filmes resultaram em maiores valores de densidade, resistência à tração e resistência à ruptura.

ABSTRACT This study investigates the physical and mechanical properties of nanostructured films produced from Pinus sp. kraft pulp. To obtain the nanocellulose, the bleached kraft pulp was submitted to six different grinding regimes: two, five, ten, 20, 30, and 40 passes through the grinder. The influence of the number of passes was evaluated through the films’ physical and mechanical properties. The results show that the nanofibers reduced the thickness and considerably increased the density values of the fabricated films. The tensile strength increased more than 300% and the burst index was ten times higher in relation to normal papers. The more compact structure and lower porosity caused by the larger contact surface between nanofibers in the nanostructured films resulted in higher values of density, tensile strength, and burst resistance.

Abstract: The modification of wood by thermal treatments produces characteristic changes in its chemical composition and surface color and can improve the structural and esthetic quality. The objective of this paper is to evaluate the potential of near infrared and visible spectroscopy to predict the modifications in chemical composition of Eucalyptys grandis and Pinus taeda after thermal treatment. Near infrared and visible spectra were collected directly on the longitudinal surface of wood samples. The thermally modified wood of both species showed higher content of lignin and extractives than the untreated wood. There was darkening of thermally modified wood, as a result of chemical modification caused by heat. The Near infrared/visible technique identified the groups that were modified by treatment. NIR and visible spectroscopy can be used to predict chemical composition of natural or thermally treated Eucalyptus grandis and Pinus taeda.