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 In the Brazilian planted forest sector, most of the species used are from the genus Eucalyptus. Even though Southern Brazil has a suitable climate for species of the genus Pinus, the planting of frost-resistant Eucalyptus species has been increasing annually. The objective of this study was to evaluate the basic density, fiber dimensions, and chemical composition of Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus saligna, and Eucalyptus cloeziana woods. The trees used were from a six-year-old experimental plantation located in Canoinhas, state of Santa Catarina. For each species, three trees were selected, and discs were removed from each tree at 0%, 25%, 50%, 75%, and 100% of the commercial stem height. To evaluate the quality of the wood, the basic wood density, fiber dimensions, and chemical composition of the wood were determined by comparing the values between species and between the heights in the stem. The highest basic density was that of the wood of E. cloeziana; this species also had the greatest length and width of fibers. E. dunnii had the lowest levels of lignin and the highest levels of holocellulose. The highest lignin content was found in the wood of E. benthamii, E. saligna, and E. cloeziana. The relationship between wood properties and stem height was not relevant. The results highlight the tendency for higher extractives to be found at taller heights (100%), and holocellulose and lignin content are similar at all heights.

RESUMO No setor de florestas plantadas brasileiro, a maioria das espécies utilizadas são do gênero Eucalyptus. Embora o Sul do Brasil tenha clima propicio para espécies do gênero Pinus, o plantio de espécies de Eucalyptus resistentes à geada vem aumentando anualmente. O objetivo deste estudo foi avaliar a densidade básica, as dimensões das fibras e a composição química da madeira de Eucalyptus benthamii, Eucalyptus dunnii, Eucalyptus saligna e Eucalyptus cloeziana. As árvores utilizadas foram provenientes de um plantio experimental de seis anos localizado em Canoinhas, estado de Santa Catarina. Para cada espécie, três árvores foram selecionadas e os discos foram removidos de cada árvore a 0%, 25%, 50%, 75% e 100% da altura do caule comercial. Para avaliar a qualidade da madeira, a densidade básica, as dimensões das fibras e a composição química foram determinadas comparando-se os valores entre as espécies e entre as alturas no fuste. A maior densidade básica foi a da madeira de E. cloeziana; esta espécie também apresentou o maior comprimento e largura das fibras. E. dunnii apresentou os menores teores de lignina e os maiores teores de holocelulose. O maior teor de lignina foi encontrado na madeira de E. benthamii, E. saligna e E. cloeziana. A relação entre as propriedades da madeira e a altura do fuste não foi relevante. Os resultados destacam a tendência de maiores extrativos serem encontrados nas partes mais altas (100%), e os teores de holocelulose e lignina são similares em todas as alturas.

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 This study aimed to evaluate the process of cellulose extraction from yacon stem using combined pulping and bleaching processes to produce nanofibrillated cellulose (NFC). First, a chemical pulping process with NaOH was applied and, subsequently, the pulp obtained was bleached. From the chemical pulp (CP) bleached, NFC was obtained by the mechanical defibrillation in a colloidal grinder. Then, chemical composition, and infrared analysis of the pulps were performed. The pulping process showed a lower amount of extractives and lignin content, as a low yield and an excessively dark pulp. The CP bleached with NaClO2 showed the best results increased whiteness of the pulp. A suspension of NFC with fibers of 5-60 nm in diameter, high crystallinity index, and thermal stability was obtained. The results are promising and demonstrate the technical feasibility of obtaining NFC from yacon stems waste which is ideal to apply to other materials of the industry.

ABSTRACT Thermally modified wood undergoes chemical, physical, and mechanical modifications, resulting in changes in resistance to wood biodegrading agents. The objective of this study was to evaluate the resistance to biodeterioration of thermally modified wood by the industrial process VAP HolzSysteme® of Eucalyptus grandis, Pinus taeda and Tectona grandis, submitted to the Lentinula edodes fungi (brown rot) and Pleurotus djamor fungi (white rot), and to analyze the chemical properties, contents of holocellulose, lignin, total extracts, and ash, before and after biodeterioration. Three treatments were considered for each species: Control - wood in natura, modified wood at 140 °C and 160 °C. The specimens were made according to ASTM D 1413 (ASTM, 1994), in a total of 108 samples per species, 36 per treatment for each species, with 12 samples submitted to the fungus L. edodes, 12 to P. djamor and 12 correction blocks. Different behaviors occurred among species under fungal action. For E. grandis wood the thermal modification increased the resistance to biodeterioration of the wood under the action of the L. edodes fungus, in the opposite way occurred for the species P. taeda. There was little variation between treatments in T. grandis wood for both fungi. Thermal modification conferred chemical alterations on the wood, influencing their behavior the biodeterioration by the fungal action in P. taeda species in a negative way, (increasing the degradation level), and E. grandis in a positive way, reducing the biodeterioration. However, in T. grandis species no significant differences were identified in the different treatments by the action of different rotting fungi.

ABSTRACT The basic density is the main technical property of the wood due to the fact of the easy determination and correlation with the others wood properties. In this article, it was evaluated wood chips from a five-years-old Eucalyptus grandis in three different silvicultural treatments for pulp and paper production. First, a conventional kraft pulping was executed in the same conditions and then submitted to some elemental chlorine free (ECF) bleaching process to achieve the target brightness of 88 ± 1% ISO. The bleached pulps were refined in a Jokro Mill at 0, 2250, 4500 and 6750 revolutions and their physical, mechanical and optical properties were analyzed. The statistical analysis indicated a difference in the wood basic density from the different silvicultural treatments. The yield of the pulping process was not affected by the variation of the wood basic density. The denser wood had the advantage of a lower specific wood consumption while the disadvantage was a greater difficulty in the delignification and a decrease in the selectivity of the pulping process. The denser wood was the one with the best bleachability and the one that most consumed chlorine in the bleaching process. The increase of the wood density caused gains in the fisical and optical properties of the bleached pulp and losses in the mechanical properties.The optical properties of the pulps from denser woods are more resistant than the negative effects of mechanical properties.

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 In this work, we studied the infl uence on the mechanical and physical properties of paper made of pulp from recycled cardboard and paper (printing/writing and newsprint) by adding different percentages of nanofi brillated cellulose. For each type of recycled pulp, we formed paper with incorporation of 0, 5 and 10 wt% nanofi brillated cellulose. The results showed that addition of nanofi brillated cellulose reduced the paper thickness and increased the density values. Papers with nanofi brillated cellulose presented resistance properties with values statistically superior to the treatments without addition. Addition of 10 % provided the best results, with improvement of tensile, burst and tear resistance of 97, 133 and 104 %, respectively, in comparison to normal papers. The paper produced with the recycled newspaper pulp had lower increase in mechanical properties from the nanofi brillated cellulose in relation to the papers with recycled pulp from cardboard and printing and writing paper. The considerable improvement in the mechanical properties is related to the increase of hydrogen bonds between the fi bers and nanofi bers, forming a dense network, resulting in greater surface area of nanofi brillated cellulose.

Na deslignificação com oxigênio, a lignina é removida da polpa através da aplicação de elevada pressão de oxigênio, em condições alcalinas, resultando em uma menor demanda por produtos químicos na etapa de branqueamento. O objetivo principal deste trabalho foi avaliar a influência do tipo de lavagem (convencional e ácida) entre dois estágios de deslignificação com oxigênio sobre a quantidade de lignina residual e o teor de metais de transição presentes em amostras de polpa kraft de pinus com número kappa inicial de 48,5. Observou-se a redução do número kappa e da viscosidade da polpa após o tratamento com O2 em duplo estágio, além do aumento da alvura final das polpas produzidas. O teor de metais da polpa durante a deslignificação com oxigênio sofreu influência do processo de lavagem, sendo que a lavagem ácida retirou maior quantidade de íons metálicos do que a lavagem convencional. Os melhores resultados foram obtidos com a retirada do elemento manganês. A lavagem ácida entre dois estágios de deslignificação contribuiu para o controle de metais de transição, o que otimizou a utilização de reagentes químicos do branqueamento nas etapas seguintes. Conclui-se que a lavagem intermediária melhorou o desempenho do oxigênio na deslignificação de polpas de número kappa elevado realizada em dois estágios.

In the oxygen delignification lignin is removed from the pulp by applying high pressure oxygen, under alkaline conditions, resulting in a lower demand for chemicals in bleaching. The main objective of this study was to evaluate the influence of washing (conventional and acid) between two stages of O2 on the amount of residual lignin and transition metal present in samples of Pine Kraft pulp with 48.5 initial kappa. The reduction of kappa number and pulp degradation after two stages of O2 treatment with increase of final brightness on sheet produced were observed. The metal content of pulp during oxygen delignification was influenced by washing process, and the acid wash removed more percentage of metallic ions than conventional wash. The best results were obtained with the removal of the element manganese. The acid wash between two stages of delignification contributed to the control of transition metals, which optimize the use of bleaching reagents in the following steps. We concluded that the intermediate washing improves the performance of the oxygen delignification of high kappa number pulps performed in two stages.

RESUMO O bambu é uma planta monocotiledônea de origem tropical, de rápido crescimento, sendo considerado um importante regenerador ambiental devido ao seu sistema radicular. O Dendrocalamus giganteus é popularmente conhecido por bambu-gigante, sendo uma espécie entouceirante de grande porte, cujos colmos podem variar de 24 a 40 metros de altura, com diâmetros entre 10 e 20 cm. Esse trabalho teve como objetivo analisar quimicamente os colmos do bambu-gigante visando fornecer informações sobre a sua composição química nas idades de 2 a 6 anos. Os colmos do bambu foram coletados na área Experimental Agrícola do Departamento de Engenharia Mecânica da UNESP-Bauru, onde é realizado o manejo sistemático de diversas espécies de bambu para fins de pesquisas e divulgação dessa planta. Foram retiradas amostras da base entre bambus com idade de 2 a 6 anos de uma mesma touceira, totalizando 5 amostras, com 2 metros de altura cada, colhidas na lua minguante no mês de março. As análises químicas foram feitas com os entrenós, utilizando as normas e procedimentos da TAPPI. A porcentagem média de extrativos em água quente, extrativos em água fria, extrativos totais e teor de cinzas não apresentaram relação direta com a idade. A maior porcentagem de extrativos em água quente, com valor de 12,04%, extrativos em água fria, com 10,25%, e extrativos totais, com 12,91%, foi observada aos 2 anos de idade. A maior porcentagem de cinzas foi obtida aos três anos, com valores de 1,09%. O teor médio de extrativos em NaOH diminui de 25,72% aos dois anos para 20,17% aos seis anos de idade. O mesmo comportamento foi observado para os extrativos em etanol tolueno, diminuindo de 10,91% para 4,61%. O teor médio de lignina não sofreu influência da idade, variando de 22,66 a 24,11%.

ABSTRACT Bamboo is a monocotyledon of tropical origin which grows fast and is considered an important environment regenerator because of its root system. Dendrocalamus giganteus is popular learned by giant bamboo, being a big bush species, its culms can be from 24 to 40 meters high, with diameters from 10 and 20 centimeters. This work had the objective of a chemical analysis from giant bamboo to aim at giving information from its chemical composition from 2 to 6 years of age. Bamboo culms were collected in the Agriculture Experimental area of the Mechanical Engineering Department of UNESP - Bauru, where it is carried out the systematic handling from different bamboo species to this plant research and divulgation. Samples from base were collected from 2 and 6 years in the same bush, in total of 5 samples, with 2 high meters each, cropped in March, half-moon. Chemical analysis was done with internodes using TAPPI Methods. The average percentage extractives from hot water, cool water, total extractives and ash content were not related to the age. The major percentage of hot water extractives, with values of 12.04%, cold water extractives, with 10.25%, and total extractives, with 12.91%, was observed by the age of two years. The major ash content was obtained on three years, with value of 1.09%. The mean value of NaOH extractives decreased from 25.72%, in two years, to 20.17% at six years old. The same behavior was observed for ethanol toluene extractives, decreasing from 10.91% to 4.61%. The mean lignin content was not influenced by age, varying from 22.66 to 24.11%.

ABSTRACT This paper was developed to evaluate the quality of structural plywood using the phenolic surface film. The plywoods were manufactured using five veneer of Pinus taeda with 2 mm thickness. The boards were pressed with temperature of 140ºC and 160ºC; specific pressure of 1,5 and 2,0 MPa; press time to achieve the temperature of resin curing, plus 1 and 2 minutes. The results of the glue line tests - dry and humity, showed that the use of press temperature of 160ºC and specific pressure of 2,0 MPa, are the better conditions to plywood manufatures using phenolic surface film. Using the better conditions of press parameters to board pressing, the plywood manufactured with phenolic surface film could present higher bonding quality in comparison to plywood manufactured with the liquid phenolic resin.

RESUMO Este trabalho foi desenvolvido com o objetivo de avaliar a qualidade de compensados estruturais com colagem à base de papel impregnado com resina fenólica - filme fenólico. Foram produzidos compensados compostos de cinco lâminas de Pinus taeda com 2 mm de espessura. Os painéis foram prensados com temperatura de 140ºC e 160ºC; pressão específica de 1,5 e 2,0 Mpa, tempo de prensagem real e acrescidos de 1 e 2 minutos. Os resultados da resistência da linha de cola nos testes seco e de fervura demonstraram que o emprego de temperatura de 160ºC e pressão específica de 2,0 MPa seriam as condições mais adequadas para a prensagem de painéis compensados com filme fenólico. Com o emprego de condições adequadas de prensagem, os compensados produzidos com filme fenólico podem apresentar qualidade de colagem superior em relação aos compensados produzidos com resina fenólica na forma líquida.