Abstract The objective of this research was to develop a more sustainable composite and still keep its characteristics. Fibers treated with NaOH at 5% w/w for 2 hours were incorporated into natural rubber in different proportions (0 phr, 24 phr, 36 phr, 48 phr and 60 phr). The mechanical properties of the composites suffered changes, increasing the hardness, young’s modulus and decreasing its tensile strength. All the physical properties were not statistically different. The coloration became less dark in the WF60/CB0 treatment, and the electrical properties presented better resistivity with the increase in the concentration of fibers in the composite. This presents a possibility of using WF for the production of wood-rubber composites for the production of rubber artifacts which do not require high rolling resistance. Based on the results from this research, we recommended the WF24/CB36 mix to produce antistatic floors.

Abstract Juvenile wood (JW) can influence the performance of structural boards since it presents lower physical and mechanical properties. This study aimed evaluate the influence of JW proportion on density and modulus of elasticity (MOE) on boards for structural use. Pinus taeda logs 30 years old, had growth rings manually counted (on the pith to bark direction), and the first six rings were painted with color red (0-6), followed by blue (6.1-12), orange (12.1-18), green (18.1-24), and yellow (over 24.1), successively, and cut into boards. The proportion of each color was obtained by analysis of the transversal areas of boards with software. MOE was obtained by a nondestructive test. Multiple linear regression models were applied with 5% of significance. The estimated MOE indicates that boards with at least 57% of orange and green colors (between 12.1 – 24 years old) can achieve the minimum MOE value for using as structural as well as boards without red color but with the presence of green and yellow can have MOE bigger than 7000 MPa. The study indicates a behavior tendency about which proportion and mixed colors can affect the MOE of the board to be classified as structural.

ABSTRACT The aim of this study was to evaluate the effect of the alkalization with different concentrations and time combination in the modification of lignin, hemicellulose and cellulose in pine fibers and determine the best combination aiming the incorporation in plant-based composites. The alkalization process was conducted with 5 concentrations (5, 10, 15, 20, and 30%) and 2 exposure times (2 and 24 hours). Chemical analysis was performed, and cellulose crystallinity, thermal stability, and surface modification were analyzed for the treated fibers. The results showed that there was a reduction in crystallinity with cellulose I – II transformation. Thereafter, the thermal stability and surface characteristics were increased with the increase of the NaOH concentration. Although all treatments altered the fiber properties, the condition that resulted in technical gain was the condition with 5% concentration and 2 hours of alkalization. Thus, we can conclude that this condition changes the macromolecular structure of the wood fibers, change the surface and the treat fiber could be used as filler to plant-base composite.

Abstract: The objective of this study was to evaluate the density, chemical properties and bonding quality of two lesser-used Mozambican wood species known as messassas (Brachystegia spiciformis and Julbernardia globiflora) aiming at edge-glued panel production. The bonding was performed using structural adhesive polyvinyl acetate D4, semi-structural adhesive emulsion polymer isocyanate and non-structural polyvinyl acetate D3 applied at 120·m-2 and 180·m-2 weights. Density, chemistry, edge shear bonding, wood failure percentage and the finger-joint tests were performed in accordance with standards. The results showed that both species have medium density, high extractives and lignin contents typical of tropical wood. The emulsion polymer isocyanate adhesive was approved with better performance compared to polyvinyl acetate D3 and D4 adhesives. It can also be affirmed that Brachystegia spiciformis and Julbernardia globiflora have similar bonding behaviour and the potential for producing edge glued panel panels, especially for indoor use.

Abstract: The objective of this research was to evaluate the physical-mechanical properties of wood-cement boards produced with waste particles of Pinus spp. and sufficient levels of pozzolans to assimilate all Ca(OH)2 produced during the hydration reactions of Portland cement. The pozzolans used were: silica fume, metakaolin, rice husk ash, and calcined ceramic waste. The values of the pozzolans were determined based on the theoretical determination of the Ca(OH)2 content produced by the hydration reactions of Portland cement. The pozzolanic activity index was determined by the modified Chapelle test. The boards were produced through cold compression, and the test specimens were produced and tested for physical and mechanical properties at 28/91 days of curing. The minimum values employed in the Bison® commercial process were used as a reference for the physical-mechanical characterization. The boards produced presented good physical-mechanical properties even with high levels of replacement of cement by pozzolans. These properties were similar to the ones presented by the reference boards, despite the significant reduction in the specific mass of the prototype boards, which demonstrates the technological possibility of the use of these materials in the production of wood-cement boards.

ABSTRACT This research aimed at evaluating the quality of bonded joints of Eucalyptus wood by using different faces and adhesives to produce EGP (Edge Glued Panels). Glue line shear specimens were obtained from bonded joints glued with PVAc (Polyvinyl Acetate) and EPI (Emulsion Polymer Isocyanate) adhesives, using pieces oriented with tangential, radial and intermediary faces, as well as the combination between them. The specimens were submitted to two pretreatments in order to simulate the use of joints in dry and wet environments. For shear tests, 12 treatments were obtained. The results indicated that the use of tangential x tangential and tangential x intermediary bonding faces and EPI adhesive presented better glue line shear strength for EGP in dry and wet pretreatments, respectively. The joints bonded in the radial x radial direction presented statistically inferior values when compared to the other treatments.

Resumo O objetivo deste trabalho foi avaliar o potencial das madeiras de Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus grandis, Eucalyptus saligna e Eucalyptus urophylla, para produção de painéis colados lateralmente (EGP) e madeira laminada colada (MLC). As propriedades físicas e químicas das madeiras foram determinadas com base nas normas COPANT 461/459:1972 e TAPPI 204/252:2002. Foram confeccionadas juntas coladas com adesivo acetato de polivinila (PVA), com gramaturas de 150 g m-2 e 200 g m-2, e resorcina-formaldeído (RF), com 200 g m-2 e 300 g m-2. A qualidade de colagem foi avaliada por meio de ensaios de cisalhamento, com base na norma EN 13354:2008. Todas as espécies apresentaram densidade básica de média a baixa e anisotropia de contração de média a alta. O teor de extrativos totais e pH estão dentro da faixa referenciada na literatura. As avaliações dos resultados com base nos requisitos da norma EN 15353:2008 para 5º percentil inferior indicaram que as espécies E. benthamii, E. dunnii, E. grandis e E. saligna, apresentam potencial para produção de painéis EGP com adesivo PVA, para o uso interno, e externo com cobertura. Para a colagem com adesivo RF, o E. dunni apresentou melhores resultados, sendo indicativo do seu bom potencial para a produção de madeira laminada colada, visando aplicações estruturais em ambientes interno úmido e externo. Para os dois tipos de adesivos o aumento na gramatura não afetou os resultados de cisalhamento das juntas coladas.

Abstract The objective of this work was to evaluate the potential of wood of Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus grandis, Eucalyptus saligna and Eucalyptus urophylla for the production of edge glued panels (EGP) and glued laminated timber (Glulam). Physical and chemical properties of the wood were determined based on the COPAN 461/459:1972 and TAPPI 204/252:2002 standards. Glued joints were manufactured in resin weights of 150 g m-2 and 200 g m-2 for polyvinyl acetate (PVA) and 200 g m-2 and 300 g m-2 for resorcinol-formaldehyde (RF). Bonding quality was evaluated by shear tests based on EN 13354-2008 standard document. All species presented medium to low basic density and medium to high contraction anisotropy. The total extractives content and pH are within the range referenced in the literature. The evaluation of the results based on the requirements of standard document EN 15353-2008 for the 5th lower percentile indicated that the E. benthamii, E. dunnii, E. grandis and E. saligna species showed high potential for the production of EGP with PVA adhesive, for indoor and outdoor use with coverage. For RF adhesive bonding, E. dunni showed better results, being indicative of its good potential for the production of glued laminated timber - GLULAM, for structural applications in the external environment. For both types of adhesives, the increase in weight did not affect the shear results of bonded joints.

Abstract This study evaluated the quality of the particleboard produced with particles generated from mobile discharges with mixture of equal parts of industrial particles of Pinus. The material was collected and processed in the form of chips by a company specialized in waste recycling. The experimental plan consisted in producing panels with nominal density 0.55, 0.70 and 0.85 g/cm3, and urea-formaldehyde resin of 8, 10 and 12%. The increased density and resin content contributed to improve the physical and mechanical properties of the panels. The panels produced with nominal density of 0.70 and 0.85 g/cm3, and 10% resin content, showed better feasibility of using mobile discharges particles in a proportion of 50% mixture with particles of Pinus industrial production of particleboards.

RESUMO O objetivo do trabalho foi avaliar a viabilidade de uso da resina lignina-fenol-formaldeído na produção de painel aglomerado estrutural de Mimosa scabrella Benth (bracatinga). Os painéis foram produzidos com massa específica nominal de 750 kg.m-3 e 950 kg.m-3, 10 e 12% de resina fenol-formaldeído e lignina-fenol-formaldeído, e 10 e 12 minutos de prensagem. A qualidade dos painéis experimentais foi avaliada por meio de seguintes ensaios físico-mecânicos: massa específica, razão de compactação, absorção de água e inchamento em espessura 2 e 24 horas, tração perpendicular, flexão estática e arrancamento de parafuso. Foram constatadas interações positivas da massa específica, teor de resina e tempo de prensagem nas propriedades dos painéis produzidos. A avaliação dos resultados das propriedades com base nos requisitos da norma EN 312:2003 (tipo P5), indicaram a viabilidade de uso da resina lignina-fenol-formaldeído na produção de painel aglomerado de Mimosa scabrellla para aplicações estruturais.

ABSTRACT The objective of this work was to evaluate the feasibility of using lignin-phenol-formaldehyde resin in the production of Mimosa scabrella Benth (bracatinga) structural particleboard. The boards were produced with nominal specific mass of 0.75 and 0.95 g/cm3, 10% and 12% of phenol-formaldehyde and lignin-phenol-formaldehyde resins, with 10 and 12 min of pressing time. The boards quality was evaluated by means of the following physical-mechanical tests: specific mass, compression ratio, water absorption and thickness swelling after 2 and 24 hours soaking, perpendicular traction, static bending and screw pulling. Positive interactions of specific mass, resin content and pressing time were observed in the properties of the boards produced. The evaluation of the properties results based on the requirements of EN 312 (type P5) standard indicated the feasibility of using lignin-phenol-formaldehyde resin in the production of particleboard of Mimosa scabrellla for structural applications.

Abstract: The objective of this study was to evaluate the feasibility of construction and demolition (C&D) waste wood to produce of particleboard. The raw material was obtained from a waste recycling company and it was divided into four types of materials: MDF (medium density fiberboard), MDP (medium density particleboard), plywood and timber. After reduction of these wood product residues to particles, particleboards were produced, in the UFPR Laboratory, with urea-formaldehyde resin and a target density of 0,75 g / cm³ and their physical and mechanical properties were determined. Particleboards made from industrial Pinus spp. particles were also produced as control samples. C&D wood waste showed potential for use as raw material for particleboard. The properties of particleboard made of recycled timber, MDP, plywood and the mixture of the four sources of material indicated that particleboard industries could use these waste resources for the production of the inner layer of MDP products.

Abstract: This study aimed to determine the influence of specific gravity on properties of oriented strand boards produced with five Eucalyptus species and get linear models between the properties and the densification of the panels. The species studied were: Eucalyptus benthamii, E. dunni, E. grandis, E. saligna, E. urograndis and the mixture between them. The panels were produced with phenol formaldehyde resin and nominal densities of 0,65 g/cm³ and 0,75 g/cm³. The water absorption has an inverse relationship to the density of the panel. The relation between mechanical properties and specific gravity of the panel is directly proportional. The panels produced with the Eucalyptus species showed better properties than those produced with control species (Pinus taeda), except for tensile perpendicular. By means of linear models obtained in this study conditions for each species, it can estimate the specific gravity to produce oriented strand board panels that adequate the standard requirements.

Resumen: El objetivo de este estudio fue determinar la influencia de la masa específica de tableros OSB producidos con cinco especies de Eucalyptus en sus propiedades y obtener modelos lineales entre las propiedades y la densificación de los tableros. Las especies estudiadas fueron: Eucalyptus benthamii, E. dunni, E. grandis, E. saligna, E. urograndis y una mezcla entre ellas. Los tableros fueron producidos con resina fenol-formaldehído y las densidades específicas nominales fueron de 0,65 g/cm³ y 0,75 g/cm³. La absorción de agua tiene una relación inversa a la densidad específica del tablero. La relación entre las propiedades mecánicas y la densidad específica del tablero es directamente proporcional. Los tableros producidos con las especies Eucalyptus presentaron mejores propiedades que los producidos con la especie testigo (Pinus taeda), excepto para la tracción perpendicular. La mezcla compenso los valores de cohesion interna en la elaboración del tablero. A través de modelos lineales obtenidos en las condiciones de este estudio para cada especie, se puede estimar la densidad específica para producir tableros de hojuela orientada que cumplen con los requisitos reglamentarios.

Resumo Esta pesquisa teve como objetivo avaliar a qualidade de painéis aglomerados produzidos com seis espécies de madeiras tropicais da Amazônia: Byrsonima crispa, Eschweilera coriacea, Eschweilera odora, Manilkara amazonica, Pouteria guianensis e Swartzia recurva. Foram produzidos painéis experimentais com densidade nominal de 0,75 g/cm3, utilizando a resina uréia-formaldeído na proporção de 8% de sólidos - base peso seco das partículas. Os painéis foram prensados com pressão específica de 4,0 MPa, temperatura de 160 ºC e tempo de prensagem de oito minutos. Os painéis foram avaliados com base nas seguintes propriedades: razão de compactação, absorção de água e inchamento em espessura 2 horas e 24 horas, módulos de elasticidade e de ruptura, tração perpendicular, resistência ao arrancamento de parafusos na superfície e topo. A baixa razão de compactação dos painéis produzidos comas espécies tropicais não afetou de forma significativa os resultados de suas propriedades físicas e mecânicas. Avaliações comparativas dos resultados obtidos com os requisitos da norma EN 312 (2003) e espécie referencial - Pinus taeda, demonstraram que as espécies Byrsonima crispa, Eschweilera coriacea, Eschweilera odora e Pouteria guianensis apresentam grande potencial para produção de painéis aglomerados.

Abstract This research aimed to evaluate the quality of particleboard produced with six Amazonian tropical woods: Byrsonima crispa, Eschweilera coriacea, Eschweilera odora, Manilkara amazonica, Pouteria guianensis and Swartzia recurva. Experimental panels were produced with nominal density of 0,75 g/cm³, using the urea-formaldehyde resin in a proportion of 8% solids based on dry weight of the particles. The panels were pressed with a specific pressure of 4,0 MPa, temperature of 160 °C and pressing time of eight minutes. The panels were evaluated based on the following properties: compression ratio, water absorption and thickness swelling for 2 hours and 24 hours, modulus of elasticity and modulus of rupture, tension perpendicular, screws pullout resistance on the surface and top. Low compression ratio of panels produced with tropical wood species did not affect significantly the results of their physical and mechanical properties. Comparative evaluation of the results obtained with the requirements of EN 312 (2003) and reference species - Pinus taeda, showed that Byrsonima crispa, Eschweilera coriacea, Eschweilera odora and Pouteria guianensis have great potential for the production of particleboard.

ABSTRACT The objective of this study was to evaluate the technical viability of Cordia trichotoma and Grevillea robusta wood for the production of plywood panels, as well as to verify the behavior of these species in combination with Pinus taeda and Eucalyptus saligna. Panels were produced using veneers of each species and in combination, totaling 8 treatments. The panels were glued with urea-formaldehyde using grammage of 180g/m2; pressed at a temperature of 110 °C, with pressure of 1MPa and a pressing time of 8 minutes. The results of the density, moisture content, superficial and total water absorption, static bending and shear tests of the core, face and back-face veneers, indicated the viability of Cordia trichotoma and Grevillea robusta for the production of plywood for interior purposes using all veneers of these species, as well as, in the production of decorative plywood manufactured using Pinus or Eucalyptus veneers.

ABSTRACT There has been ever growing interest in the construction industry in using lighter, eco-friendly and sustainable materials, while maintainingthe desirable mechanical properties. The objective of the present work was to evaluate the effects of pre-treatments on chemical compatibility between Curauá fiber (Ananas erectifolius) and Portland cement. In the inhibition test, cement hydration temperature evolution wasmeasured in the absence and presence of untreated and treated Curauá fibers (cold water, hot water and NaOH). The chemical characterization of untreated Curauá fibers was done by determining the content of extractives, lignin, holocellulose and ashes. Thee Segal's method was used for determinate the crystallinity index on untreated and treated fibers. The inhibition test graded the untreated fiber as high inhibition, showing the need to provide it a treatment. Treatments done on Curauá fibers removed some amorphous components of the fibers affected positively the compatibility between cement and fiber, and reducing the inhibition.

RESUMO O objetivo deste estudo foi avaliar a viabilidade técnica da utilização de cinco espécies de Eucalyptus, provenientes de plantios com ciclo de curta rotação, para produção de painéis OSB. As espécies estudadas foram: Eucalyptus benthamii, Eucalyptus dunni, Eucalyptus grandis, Eucalyptus saligna, Eucalyptus urograndis, a mistura entre elas e o Pinus taeda como testemunha. Os painéis de Eucalyptus apresentaram maior estabilidade dimensional quando comparados com os painéis testemunha. Os painéis compostos pelo mix de espécies apresentaram estabilidade dimensional semelhante aos demais produzidos com as espécies de Eucalyptus puras. No ensaio de flexão estática os valores de MOR não apresentaram diferenças estatísticas entre os tratamentos, porém, para MOE, os painéis de Eucalyptus apresentaram valores estatisticamente superiores quando comparados aos da testemunha. Na tração perpendicular os painéis produzidos com Pinus taeda apresentaram valor médio superior às demais espécies. Todas as espécies assim como a mistura entre elas mostraram viabilidade técnica para produção de painéis OSB.

ABSTRACT This study aimed to assess the technical feasibility of using five Eucalyptus species to manufacture Oriented Strand Boards. The species studied were: Eucalyptus benthamii, Eucalyptus dunni, Eucalyptus grandis, Eucalyptus saligna, Eucalyptus urograndis the mixture between them and the Pinus taeda as control. The panels composed by a mix of species showed dimensional stability similar to others produced with Eucalyptus pure species. The panels of Eucalyptus had lower water absorption and thickness swelling values to the controls panels. In static bending, the MOR values did not show statistics differences between treatments, however, for MOE the Eucalyptus panels showed statistically higher values when compared to control specie. In internal bond, the panels produced with Pinus taeda showed higher average value than the other species. All species as well as the mixture showed technical feasibility for the production of Oriented Strand Board.