ABSTRACT Background: The objective of the present work was to investigate the influence of a pre-treatment of microbial-rich digestate (liquid mesophilic anaerobic digestate - AD-supernatant) on the morphology, crystallinity, and thermal stability of cellulose pulp fiber. Results: The six most abundant bacteria in the AD-supernatant were determined by 16S analysis. The bacteria population was comprised mostly of Bacteroides graminisolvens (66%) and Parabacteroides chartae (28%). Enzymatic activity from the bacteria partially removed the amorphous components and increased the crystallinity and crystallite size of the cellulose substrate. The fiber pulp was incubated in AD-supernatant for 5, 10, and 20 days. The X-ray diffraction data provided evidence that the amorphous portion of the cellulose was more readily and quickly hydrolyzed than the crystalline portion. The longest incubation times (20 days) resulted in substantial deconstruction of the cellulose fiber structure and decreased the thermal degradation temperature. Conclusion: The anaerobic digestate is inexpensive and could be used to effectively aid in the pre-treatment of cellulose on large scale transformation processes, e.g. for making biofuels, cellulose micro/nanofiber production or engineered fiber-based materials.

ABSTRACT The present work evaluates the effect of pyraclostrobin fungicide on the nutritional quality of mulberry leaves, silkworm cocoon production and silk fiber mechanical performance. The evaluation was performed in two consecutive years. In Spring 2015, mulberry plants were treated twice with 4 doses of pyraclostrobin (0, 100, 200, and 300 g.ha-1), 30 and 15 days before pruning of the branches. In Spring 2016, the same plants received the same doses of pyraclostrobin only 30 days before pruning of the branches. Fifth instar caterpillars were fed on treated mulberry leaves. The mineral content of mulberry leaves was determined on pruning day of the branches and 30 days before. The consumption of mulberry leaves and the mortality rate of the caterpillars fed with the treated leaves was verified, and the cocoons obtained were classified and weighed. Silk fibers were submitted to mechanical evaluation by tensile test. Morphological and physical modification were evaluated by Scanning Electron Microscope (SEM) and X-ray diffraction (XRD). In 2015, the mortality of caterpillars fed on leaves treated with pyraclostrobin was at least 26.7% higher than the control. At 2016 even with a single application the weight of the cocoons was lower. The main variation in the mineral content was observed in Mn and Fe nutrients. Mineral intake had a noticeable effect in both crystallinity and tensile strength. Results show that the use of pyraclostrobin may reduce the mechanical behavior of silk thread up to 70%, indicating that its use is not indicated for mulberry planting aiming silk feeding.

ABSTRACT Background: During de-pulping of açai (Euterpe oleracea) for juice production in the Amazonia, large amounts of fibrous waste are daily discarded, a promising substrate for production of high-value cellulose nanofibrils. Therefore, this study sought to evaluate the modifications of açai surface fibers submitted to chemical pretreatment steps and compare the quality of nanostructured films produced with different cycles of mechanical nanofibrillation. Results: A 2-hour pretreatment (at 5% of NaOH) followed by two NaOH/H2O2 bleaching steps resulted in fibers with increased length and reduced diameter compared to raw fibers while preserving fiber integrity and cellulose I structure. The increase of fibers’ grinding cycles from 3 (minimum to gel point) to 21 (maximum suspension thickness) resulted in nanofibril films with higher crystallinity properties, uniform thickness, compacted morphology, and smoother surface. Nanofibril films formed after different numbers of passages exhibited similar mechanical strength, but distinct barrier properties. Conclusion: Açaí waste films produced with fibers submitted to 3 grinding cycles can be recommended for packaging applications that demand easily dissolving, such as instantaneous food. Oppositely, açaí fibers subjected to 21 cycles in grinder provide films suitable for water-resistant packaging, ideal for secondary coatings of papers and paperboards.

ABSTRACT Wood is a natural material that presents a great variation of properties. Many treatments have been developed in order to extend the service life of wood products. Nowadays, products with low toxicity and economic viability are a challenge to researchers. Nanotechnology has been indicated as a solution to this issue, since wood preservatives can be utilized in low concentration, promoting satisfactory results in terms of protection with no color changes. The main goal of this review is to present nanotechnology advances on wood protection. Self-cleaning surfaces, scratch and weathering resistance, and biocides properties have been achieved through nanoparticles (NPs) applications. Studies evaluating the performance of NPs from silver (Ag), boron (B), copper (Cu), zinc (Zn), zinc oxide (ZnO), zinc borate (B2O6Zn3), and titanium dioxide (TiO2) on wood protections have reported promising findings. Tests performed against termites, rot, mold and stain fungi, and UV degradation have demonstrated that some biocides have their properties improved in nanoscale. Controlled release and encapsulation technologies are another important matter once it can increase the effectiveness of wood treatments. NPs risk assessment for human health and the environment are still incipient. Despite of that, some products as nanozinc oxide (nanoZnO) and titanium dioxide (nanoTiO2) present encouraging potential. NanoZnO and NanoTiO2 have been reported as promising antifungals, antibacterials, and antiviral agents; beyond theirs biocides properties, low ecotoxicity impacts to the environment are expected. Based on this review, we consider that wood treatments based on NPs may play an important role in the next generation of wood protection systems.

ABSTRACT The objective of this study was to evaluate the polyester-based fiber composites reinfor ced with filaments/fibers of mauve treated with NaOH and maleic anhydride. The che mical treatment of the mauve filament/fibers (3 cm of length) was carried out, first with NaOH, followed by maleic anhydride. The resin used was ortho unsaturated polyester with addition of catalyst peroxide methyl ethyl ketone. The composites were prepared with 15% filaments (w/w) and tested for water absorption, three-point bending, tensile and impact strength. Fiberglass composites were produced using the same methodology for comparison purpose. The results demonstrate the potential use of mauve filaments. For some properties, the mauve composites showed better mechanical properties than fiberglass composites (three-point bending and tensile). The treatment of the filaments had varied effect and did not improve the mechanical properties. However, for the water absorption was observed a reduction of 35% in composites with treated mauve filaments.

RESUMO O interesse em nanocristais de celulose obtidos a partir de recursos naturais tem crescido principalmente devido a características que esses materiais fornecem quando inseridos em matrizes poliméricas. O presente estudo teve como objetivo avaliar o efeito da adição de nanocristais de celulose nas propriedades mecânicas dos biofilmes feitos a partir de hipromelose (ou hidroxipropil metilcelulose - HPMC) e misturas com amido de mandioca (CS). Os nanocristais de celulose foram produzidos por hidrólise ácida e caracterizados por microscopia óptica (OM), microscopia eletrônica de transmissão (TEM), difração de raios X (XRD) e termogravimetria (TG). Os filmes foram feitos por fundição (ou “casting”) com CS puro, hipromelose pura e também com misturas de CS e hipromelose. Em seguida, os nanocristais de celulose foram adicionados às misturas nas concentrações de 1, 3 e 10% (m/m). As avaliações dos filmes incluíram a resistência a tração e a superfície da fratura por microscopia eletrônica de varredura (SEM). Observou-se que o reforço com nanocristais de celulose melhorou as propriedades mecânicas, e as observações da superfície de fratura dos filmes testados mostraram que os nanocristais promoveram uma melhora na coesão da hipromelose e do amido na mistura e promoveram uma superfície mais homogênea.

ABSTRACT Interest in cellulose nanocrystals obtained from natural resources has grown mainly because of features that such materials provide when inserted into polymeric matrices. The present study aimed to evaluate the effect of cellulose nanocrystals addition on mechanical properties of biofilms made from hypromellose (or hydroxypropyl methylcellulose - HPMC) and cassava starch blends (CS). The cellulose nanocrystals were produced by acid hydrolysis and characterized by optical microscopy (OM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetry (TG). Films were made with pure CS, pure hypromellose and also with blends of CS and hypromellose by casting. Then cellulose nanocrystals were added to the blends in the concentrations of 1, 3 and 10% (m/m). Evaluations of the films included tensile performance and fracture surface by scanning electron microscopy (SEM). It was observed that the reinforcement with nanocrystals improved the mechanical properties of the films, and their fracture surface showed that cellulose nanocrystals promoted an improvement in the cohesion of the hypromellose and starch molecules in the blend, and created a more homogeneous surface.

The present study was to evaluate the effect of polyethylene terephthalate (PET) particle sizes on the mechanical and physical properties of extruded fiber-cement composites with different particle sizes combined to cellulose pulp in the production of fiber cement by the extrusion process. The design consisted of four formulations, one composed of 5% cellulose and the other three with 2.5% cellulosic pulp and 2.5% of PET particles with different particle sizes. Physical, mechanical and microstructural tests were performed without aging cycles and after 200 and 400 accelerated aging cycles. The degradation of vegetable fibers in the cement and the decrease of properties with aging was observed. PET particles were more resistant in alkaline environment and did not degrade. However, particle size did not exert great effect in the physical and mechanical properties of the composite. Thus, the use of PET particles shows potential as a reinforcement for fiber-cement composites.

The aim of this study was to evaluate the potential use of sisal and coir fibers in combination with Eucalyptus particles for the production of particleboard. The particleboards were produced in three layers. The first and third layers (face) were made with small Eucalyptus particles. The second layer (core) was made with big Eucalyptus particles in combination with coir or sisal fibers. The particleboards were prepared with the substitution on Eucalyptus wood for sisal and coir fibers in the particleboards core, in doses of 0, 10, and 20%, relative to the total mass of particles. The particleboards were characterized by mechanical, physical and thermal properties. The results were not satisfactory for particleboards with sisal. However, for coir particleboards the physical-mechanical properties were very similar to those particleboards produced only with Eucalyptus. This work demonstrates the potential use of the coir that is commonly disposed in landfills on the Brazilian beaches.

RESUMO Uma forma alternativa para produção de fibrocimento é a extrusão, que permite entre muitas vantagens a produção de compósitos cimentícios com geometrias diferenciadas e requer baixo investimento inicial para produção industrial. Nesse contexto,o objetivo desse trabalho foi obter micro/nanofibrilas celulósicas de Eucalyptus e avaliar o efeito da adição de diferentes conteúdos dessas micro/nanofibrilas nas propriedades físico-mecânicas de fibrocimentos envelhecidos naturalmente e em ambiente climatizado. Micro/nanofibrilas celulósicas produzidas em desfibrilador mecânico foram caracterizadas quanto a sua morfologia. Compósitos extrudados produzidos com 0,5% e 1,0% (em massa) de micro/nanofibrilas foram comparados com compósitos sem micro/nanofibrilas. Compósitos produzidos a partir das três formulações foram submetidos aoenvelhecimento natural e em ambiente controlado para posterior caracterização por flexão estática, vibração flexural e propriedades físicas. Não houve diferença significativa no módulo de ruptura (MOE), limite de proporcionalidade (LOP), e deformação específica total entre os compósitos com reforço de 0,5 e 1,0% de micro/nanofibrilas e aqueles sem reforço. O módulo elástico estático (MOE) aumentou, e a energia específica diminuiu com 1,0% de micro/nanofibrilas. O módulo de elasticidade dinâmico (E) dos compósitos aumentou com o incremento do conteúdo de micro/nanofibrilas (1,0%) e do tempo de exposição ao envelhecimento natural e controlado. O presente estudo indica que as propriedades físicas (absorção de água - AA, porosidade aparente - PA e densidade aparente - DA) e mecânicas de fibrocimentos são sensíveis à formulação e que esse comportamento varia em função do tempo (135 dias). Essas informações devem ser consideradas úteis para o desenvolvimento de novos materiais reforçados com micro/nanofibrilas de celulose.

ABSTRACT Extrusion is an alternative process for fiber-cement production and allows many advantages such as different geometries for the extruded products and the low initial investment for industrial production. In this context the aim of this study was to produce cellulose micro/nanofibrils from Eucalyptus pulp and evaluate the properties of cementitious composites made with different contents of cellulose micro/nanofibrils. Cellulose micro/ nanofibrils were produced using a mechanical defibrillator, and characterized for their morphology. Extruded composites were produced with 0.5 to 1.0% (by mass) of micro/ nanofibrils and compared to unreinforced composites. Composites reinforced with 1.0% of micro/nanofibrils presented higher water absorption and apparent porosity than their counter parts. No significant differences were observed for modulus of rupture (MOR), limit of proportionality (LOP) and final specific deformation, between the composites reinforced with 0.5% and 1.0% of micro/nanofibrils and those with no reinforcement. The static elastic modulus (MOE) increased and specific energy decreased with the inclusion of 1.0% of micro/nanofibrils. Dynamic elastic modulus (E) of the composites increased with the increase of micro/nanofibrils content and of weathering exposition. This study indicates that fiber-cements are sensitive to changes in structural composition and time of ageing (135 days). This information can be useful for developing of new products based on cellulose micro/nanofibrils.

The objective of the present study was to evaluate lignocellulosic particles from sub-products of the coffee industry (coffee parchment - CP and husk - CH) into polyhydroxybutyrate (PHB) as a promising reinforcing filler in the biocomposites. The effects of type (CP or CH) and content (neat, 10% and 20%) of coffee wastes on the thermal, mechanical, microstructural and physical properties of the ensuing composites were evaluated. Thermal stability of the composites was improved by the coffee residues at different contents, while degree of crystallinity was decreased with the inclusion of CP. The addition of 10% of CP has not influenced significantly the tensile strength (TS) and Izod strength (IS), in relation to the neat PHB. Tensile strength (TS), MOE and Izod strength (IS) of the composites have increased significantly with the inclusion of 20% of CP. The increase in the content of coffee waste particles increased the water absorption of the composites.

Objetivou-se, neste trabalho, avaliar, por meio da análise de componentes principais, a qualidade da madeira de Coffea arabica L. em diferentes variedades e sistemas de cultivo como fonte de bioenergia. Foram utilizadas madeiras provenientes de três sistemas de cultivo (natural, convencional e orgânico) e de duas variedades distintas (Mundo Novo e Catuaí), totalizando seis tratamentos. Foram quantificados os teores dos componentes elementares (C, H, N, S e O), de cinzas, lignina, extrativos totais e holocelulose, a densidade básica, o poder calorífico superior, o poder calorífico inferior, o poder calorífico superior e inferior volumétricos das madeiras analisadas. Foi realizada a análise estatística multivariada de componentes principais. Os escores das componentes principais de interesse foram determinados como forma de dividir as madeiras em grupos. O grupo I foi composto pela madeira do cafeeiro orgânico Mundo Novo e natural Mundo Novo; o grupo II pelo orgânico Catuaí, e o grupo III pelas madeiras dos cafeeiros convencional Mundo Novo, natural Catuaí e convencional Catuaí. Os resíduos madeireiros da espécie Coffea arabica L. apresentaram grande potencial para o uso energético, com destaque para as madeiras provenientes do sistema de cultivo convencional e da variedade Catuaí. As madeiras do grupo III se destacaram em decorrência dos elevados valores de poder calorífico volumétrico, densidade básica, teor de lignina e poder calorífico superior. Entretanto, as madeiras desse grupo apresentaram elevado teor de nitrogênio.

This work aimed to evaluate, through principal component analysis, the quality of Coffea arabica L. wood obtained from different growth systems and varieties as a source of bioenergy. Wood from three different growth systems (natural, conventional and organic) and two different varieties (Mundo Novo and Catuaí) were used, totalizing six treatments. The contents of elementary components (C, H, N, S and O), ash, lignin, total extractives and holocellulose, basic density, the higher heating value, the lower heating value, as well as the lower and higher volumetric heating values of the analyzed woods were quantified. Principal components multivariate statistical analyses were conducted. The scores of the principal components of interest were determined as a way to divide the woods into groups. Group I was composed by the wood from the organic coffee "Mundo Novo" and natural "Mundo Novo"; Group II by the organic "Catuaí", and Group III by the wood from convencional "Mundo Novo", natural "Catuaí" and convencional "Catuaí". Wood residues from the species Coffea arabica L. showed great potential for energetic use, especially the woods from the conventional systems and the "Catuaí" Variety. Woods from Group III stood out, due to the high volumetric heating values, basic density, lignin content and higher heating value. However, the woods of this group showed high nitrogen content.

Neste trabalho, objetivou-se comparar a resistência das madeiras de cedro australiano (Toona ciliata) e pinus (Pinus sp.) e de painéis aglomerados produzidos com essas espécies ao ataque do cupim de madeira seca Cryptotermes brevis, bem como quantificar a mortalidade dos insetos. Foram colocados 30 pseudo-operários em placas de Petri de acrílico de 9,5 cm de diâmetro, contendo as amostras (1,5 x 1,5 x 0,5 cm) e folhas de algodão posicionadas sobre as tampas perfuradas umedecidas diariamente com 5 ml de água. As placas foram acondicionadas em BOD (Biological Oxygen Demand) a 24±5ºC e escotofase de 24 h. Uma amostra testemunha sem fonte de alimentação foi incluída no bioensaio. O cálculo do índice de deterioração (ID) das amostras e a avaliação da mortalidade foram realizados após 60 dias. Os cupins da amostra testemunha apresentaram mortalidade maior em relação aos cupins dos demais tratamentos, os quais não se diferenciaram entre si. A madeira de Toona ciliata foi mais resistente ao ataque de Cryptotermes brevis em relação à madeira de Pinus sp. Os índices de deterioração médios foram de 1,74% e 6,62% para essas madeiras respectivamente. O índice de deterioração médio do painel produzido com 100% de Toona ciliata (ID=1,58%) foi similar ao índice de deterioração do painel produzido por essa mesma espécie em mistura com Pinus sp. (ID=1,87%).

The aim of this work was to compare the resistance of Australian red cedar (Toona ciliata) and pine (Pinus sp.) woods and particleboards made from these species to dry-wood termite Cryptotermes brevis attack, as much as to quantify the mortality of the insects. 30 termite pseudo-workers were put in each 9,5 cm-diameter Petri dishes containing the samples (1,5 x 1,5 x 0,5 cm) and cotton sheets positioned on the perforated covers, daily moisturized with 5 ml of water. The dishes were maintained in BOD (Biological Oxygen Demand) at 24±5 ºC and 24 h of escotophase. A control sample without any feed source was included in the bioassay. The deterioration index (ID) and mortality of the insects were evaluated after 60 days. Termites from the control sample presented higher termite mortality than the other treatments, which did not differ among each other. Toona ciliata wood was more resistant than Pinus sp. wood to Cryptotermes brevis attack. The average deterioration indexes were 1.74% and 6.62% respectively for those woods. The average deterioration index of the panels made with 100% Toona ciliata (ID=1.58%) was similar to the deterioration index of particleboards made with this specie mixed with Pinus sp. (ID=1.87%).

O Brasil é um dos maiores produtores de banana do mundo e, consequentemente, gera uma grande quantidade de resíduos provenientes dessa cultura, os quais poderiam ser aproveitados na produção de aglomerados. No presente trabalho, objetivou-se avaliar o efeito de diferentes tratamentos químicos nas partículas de pseudocaule da bananeira Musa sp. em suas propriedades químicas e físicas (densidade básica), além da influência desses tratamentos nas propriedades físicas e mecânicas de painéis aglomerados produzidos com o mesmo material. Foram realizados 5 tratamentos nas partículas, sendo: 1) sem tratamento (testemunha); 2) ácido acético 2% ; 3) NaOH 0,5 %, 4) acetona (1/1 em volume/volume); e 5) água. Os painéis produzidos foram de média densidade (0,70 g/cm³), encolados com o adesivo ureia-formaldeído a 12% (em relação à massa de partículas). O ciclo de prensagem utilizado foi 4 MPa de pressão, a uma temperatura de 160º C, por um período de 8 min. Os resultados obtidos indicaram que todos os tratamentos químicos realizados nas partículas de pseudocaule da bananeira afetaram a composição química do material. A densidade básica das partículas do pseudocaule foi de 0,10 g/cm3 e o tratamento com NaOH foi o único que afetou essa propriedade, ocasionando seu aumento para 0,13 g/cm3. Os painéis produzidos com as partículas sem tratamento (testemunha), e com as tratadas com ácido acético foram os que apresentaram menores valores de absorção de água e inchamento em espessura após 2 e 24 h de imersão. As propriedades mecânicas de todos os painéis produzidos ficaram abaixo do mínimo recomendado pela norma CS 236-66 (COMMERCIAL STANDARD - CS, 1968).

Brazil is one of the major banana producers in the world, and consequently generates a great amount of residues from this crop, which could be utilized in particleboard production. The present work aimed to evaluate the effect of different chemical treatments of the particles of Musa sp. pseudostem, on their chemical and physical properties (basic density), and on the physical and mechanical properties of the particleboards produced with the same material. Five treatments were applied to the particles: 1) without treatment (control); 2) 2% acetic acid; 3) 0.5% NaOH; 4) acetone (1/1 in volume/volume); and 5) water. Panels with medium density were produced (0.70 g/cm³), bonded with 12% (in relation to the particle mass) of urea-formaldehyde adhesive. The pressing cycle was conducted at 160º C, under 4 MPa, during 8 min. The results obtained indicated that the chemical treatments performed in the particles of banana tree pseudostem affected their chemical composition. The basic density of the particles was 0.10 g/cm³, and only the NaOH treatment led to its increase for values around 0.13 g/cm3. The panels produced with particles without treatment (control) and particles treated with acetic acid presented the lowest values of water absorption and thickness swelling after 2 and 24 h of immersion. Mechanical properties of all the panels produced were below the minimum recommended by the standard CS 236-66 (COMMERCIAL STANDARD - CS, 1968).

RESUMO Na avaliação de resíduos lignocelulósicos para a produção de bioenergia é necessário considerar as várias características e propriedades que podem ser correlacionadas. Este fato demanda o emprego de diversas técnicas de análise multivariada que possibilitem a avaliação dos fatores energéticos mais relevantes. O objetivo deste trabalho foi aplicar as análises de agrupamento e componentes principais na seleção e avaliação de resíduos lignocelulósicos visando à produção de bioenergia. Foram utilizados 8 tipos de biomassa residual, dos quais foram determinados os teores dos componentes elementares (C, H, O, N, S), os teores de lignina, extrativos totais e cinzas, a densidade básica e o poder calorífico superior e inferior. As duas técnicas multivariadas empregadas para a avaliação e seleção de resíduos lignocelulósicos para a produção de energia foram eficientes, sendo observadas similaridades entre os grupos de biomassa formados por elas. Pela interpretação da primeira componente principal obtida, criou-se um índice de desempenho global para avaliar a viabilidade do aproveitamento energético da biomassa. A interpretação da segunda componente principal permitiu um contraste entre os teores de nitrogênio e enxofre e o teor de oxigênio.

ABSTRACT The evaluation of lignocellulosic wastes for bioenergy production demands to consider several characteristics and properties that may be correlated. This fact demands the use of various multivariate analysis techniques that allow the evaluation of relevant energetic factors. This work aimed to apply cluster analysis and principal components analyses for the selection and evaluation of lignocellulosic wastes for bioenergy production. 8 types of residual biomass were used, whose the elemental components (C, H, O, N, S) content, lignin, total extractives and ashes contents, basic density and higher and lower heating values were determined. Both multivariate techniques applied for evaluation and selection of lignocellulosic wastes were efficient and similarities were observed between the biomass groups formed by them. Through the interpretation of the first principal component obtained, it was possible to create a global development index for the evaluation of the viability of energetic uses of biomass. The interpretation of the second principal component allowed a contrast between nitrogen and sulfur contents with oxygen content.

Studies concerning the production of particleboards with sugarcane bagasse as an alternative fibrous material have been carried out as an attempt to provide a sustainable and viable destination for this residue. This work aimed to evaluate the influence of several processing variables related to the microstructure of sugarcane bagasse particleboards (mat type, adhesive type and adhesive content) on their permeability and water sorption properties. Air permeability data was collected by the rotameter method. Superficial air permeability (kg), Darcian constant (k1) and non-Darcian constant (k2) were measured. kg was related to sorption behavior of the particleboards. 1-layer particleboards presented significantly higher kg values than the 3-layer particleboards. In general, adhesive type, position and content did not influence kg of particleboards. However, these processing variables influenced interactions between fluid and material and tortuosity of the porous media. Particleboards produced with urea-formaldehyde with high kg presented higher water absorption and thickness swelling after 24 hours. Such relations were not observed in particleboards produced with melamine-urea-formaldehyde.