RESUMO Os impactos ambientais gerados por processos produtivos é um assunto em crescente evidência no mundo organizacional, e a análise comparativa de processos vem sendo utilizada pelas empresas para verificar os impactos ambientais e suas principais fontes de emissões. A análise dos impactos de um processo produtivo, com dois contextos distintos para a produção de hastes de óculos de policarbonato (PC), em uma indústria localizada no interior de São Paulo, foi realizada com a finalidade de comparar os impactos ambientais gerados. Para isso, foram definidos dois cenários: o 1 representa o processo de injeção que utiliza 100% de PC virgem como matéria-prima, enquanto o 2 usa apenas 20% de matéria-prima virgem, sendo o restante proveniente de resíduos de PC reciclados internamente. Dados quantitativos e qualitativos referentes aos cenários foram coletados e utilizados para identificar os impactos ambientais gerados com o auxílio da metodologia de avaliação do ciclo de vida (ACV). Com os resultados obtidos e a análise comparativa realizada, foi possível verificar os benefícios ambientais resultantes da reciclagem interna da matéria-prima. A redução dos impactos no cenário 2 em comparação com o 1 foi expressiva, principalmente, devido à diminuição da necessidade da produção de matéria-prima virgem. Em todas as categorias de impactos analisadas, ocorreram reduções - por exemplo, na categoria “mudanças climáticas”, a redução foi superior a 70%.

ABSTRACT The environmental impacts generated by production processes is a subject that is increasingly evident in the organizational world and the comparative analysis of processes is an effective method used by companies to verify their environmental impacts and main emission sources. The analysis of environmental impacts for a process with two different scenarios to produce Polycarbonate (PC) glasses temples, in an industry located in the region of São Paulo, was performed in order to compare the environmental impacts generated by both scenarios. Thus, two scenarios were defined: scenario 1 represents the injection process that uses 100% of virgin PC as raw material; while scenario 2 uses only 20% of virgin raw material, the remainder PC waste being internally recycled. Quantitative and qualitative data related to the scenarios were collected and used to identify the impacts generated using the life cycle assessment (LCA) methodology. With the results obtained and the comparative analysis performed, it was possible to verify the environmental benefits of using the internal recycling of raw material. The impact reduction in scenario 2, compared to scenario 1, was significant, mainly due to the decrease of the need to produce virgin raw material. There were no reductions in all impact categories analyzed; for example, reduction was over 70% in the “climate change” category.

Abstract Starches polymeric films offer several advantages for the replacement of synthetic polymers due to their biodegradability, non-toxicity, availability and low cost. However, the high biodegradation potential can cause fragility, considering some fundamental mechanical properties. Therefore, starch based polymeric films were reinforced incorporating lignocellulosic waste from coffee grounds post-consume. The effect of incorporation of coffee ground in cornstarch matrix and polymer interaction on morphology, thermal and mechanical properties were investigated. The characterization analyzes were based on Dynamic Mechanical Thermal Analysis (DMTA), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and Scanning Eletronic Microscopy (SEM). The coffee ground behaved as reinforcement agent according tensile values. Thermochemical conversion showed that polymeric films molding did not change his thermal stability. In temperature range was possible to observe the devolatilization, organic and inorganic compounds decomposition. SEM images showed the coffee ground adhesion in the polymer matrix promoting a better mechanical tensile strength.

Abstract This work shows the fractographic study of fractured surfaces resulted from tensile tests of thermoplastic composites based on poly(propylene-co-ethylene) (PP-PE) and modified PP-PE copolymers reinforced with continuous carbon fibers (CF). The PP-PE matrix was modified with two agents called AM1 (based on maleic anhydride) and AM2 (containing an elastomeric agent), respectively. Three different laminates - CF/PP-PE, CF/PP-PE(AM1) and CF/PP-PE(AM2) - were manufactured. The best tensile strength and elastic modulus results were determined for the CF/PP-PE(AM1) laminate (507.6 ± 11.8 MPa and 54.7 ± 2.4 GPa, respectively). These results show that the AM1 agent contributed to increase the physicochemical interaction between the CF and the PP-PE matrix. This condition provided a better loading transfer from matrix to the reinforcement. Scanning electron microscopy analyses of the fracture surfaces show the fractographic aspects of the samples and allow evaluating the fiber/matrix-interfacial adhesion. Poor adhesion is observed for the CF/PP-PE and CF/PP-PE(AM2) laminates with the presence of fiber impressions on the polymer rich regions and fiber surfaces totally unprotected of polymer matrix. On the other side, a more consistent adhesion is observed for the CF/PP-PE(AM1) laminate. This result is in agreement with the tensile test data and show the presence of a good interaction between the laminate constituents. The correlation of the mechanical and fractographic results with the curves of complex viscosity versus temperature of the studied polymer matrices shows that the matrix viscosity did not affect the wettability of the reinforcement.

Biodegradable polymeric composites using natural fibers have been investigated aiming to mitigate environmental impacts. In this paper, polyhydroxybutyrate (PHB) composites obtained using random mats of sisal and coconut fibers by compression molding in a hydraulic press, and the fiber content varied between 10% and 15% relative to the weight of the polymer. Thermal analyses were performed such as Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Flexural and tensile tests were performed before and after conditioning in climate chamber with temperature and moisture. The results of thermal analysis show that the thermal stability of the materials remained, both PHB without fiber as for composites with natural fibers mats. The results of mechanical tests indicated that the PHB without fibers and composites showed similar flexural strength values, while the results of the tensile test PHB without fibers showed resistance to higher tensile composite.

ABSTRACT This study evaluates the thermal, morphological and mechanical behavior of polypropylene (PP) composite with different natural fibers. The fibers used were wood, sugarcane, bamboo, babassu, coconut and kenaf with and without coupling agent. The thermal, morphological and mechanical properties were evaluated, and a composite PP+GFPP (glass fiber) was used as reference. The interaction at the interface fiber-polymer matrix was studied by scanning electron microscopy (SEM) at the fractured surface of the composites, as expected the presence of maleic anhydride (MA) as coupling agent increasedthe interaction at the interface. The influence of natural fiber in the degree of crystallinity of the composites was evaluated by DSC analysis. The samples of PP+GFPP and PP+(PP-MA)+WF (wood flour) showed better temperature stability. PP+GF also presented superior flexural modulus. The thermal dynamic mechanical behavior was evaluated by DMA, a decrease in storage modulus with increasing temperature was observed, the PP+GF and the composite containing maleic anhydride and sugarcane fiber showed higher modulus. The natural fiber biocomposites studied, consistently presented lower flexural modulus and tensile strength than the reference composite, with and without the use of coupling agent. As expected the use of natural fibers lowered the density compared to the reference material.

Este trabalho envolveu a moldagem de briquetes com utilização de resíduos de pó borra de café e serragem de madeira de eucalipto. Os briquetes produzidos a partir de biomassa vegetal podem ser aplicados como substituintes de outros combustíveis utilizados em caldeiras de processos industriais ou até mesmo para aquecimento de residências, em regiões frias, com utilização de equipamentos mais simples. No Brasil e em muitos países uma grande quantidade de resíduos de borra de café é produzida e desperdiçada no cotidiano e em indústrias de café solúvel. A serragem de madeira também é um resíduo bastante comum no Brasil, principalmente, em algumas cidades que concentram grande número de empresas que processam madeira. Assim, a moldagem de briquetes com estes resíduos sólidos é uma oportunidade de reaproveitar os resíduos para produzir um tipo de combustível proveniente de fonte renovável, contemplando também aspectos relacionados à bioenergia e Produção Mais Limpa (P+L). Desta forma, no presente trabalho foram realizadas moldagens de briquetes utilizando o pó da borra de café e serragem de madeira em diferentes proporções destes materiais para avaliar propriedades mecânicas de compressão diametral. Também foram realizadas análises para determinar os teores de umidade, voláteis e cinzas, além da determinação do poder calorífico superior (PCS). Todas as composições de briquetes contendo serragem ocasionaram acréscimos nos valores das médias das propriedades de resistência máxima à compressão diametral e módulo de elasticidade, quando comparados aos valores destas propriedades dos briquetes moldados apenas com a borra de café. As diferentes composições de briquetes contendo serragem apresentaram valores próximos de resistência à compressão diametral. Considerando os valores do poder calorífico (PCS), todas as amostras apresentaram resultados semelhantes em comparação com a literatura. Os briquetes contendo somente borra de café na composição apresentaram resultados de teores de cinzas, voláteis e PCS similares aos das amostras contendo serragem. Porém, os briquetes contendo somente borra de café apresentaram valores inferiores de resistência máxima à compressão quando comparados a todos os outros briquetes moldados também com serragem.

This work involved the molding briquettes with use of powder of coffee and eucalyptus wood sawdust residues. The briquettes produced from biomass can be applied as replacements for other fuels used in boilers for industrial processes or even for heating home in cold regions, using simple equipment. In Brazil and in many countries a large amount of waste coffee grounds is produced and wasted in daily life and in soluble coffee industry. The wood sawdust is also a fairly common residue in Brazil, especially in some cities that concentrate large number of companies that process wood. Then the molding of briquettes with these solid wastes is an opportunity to reuse the waste to produce a type of fuel from renewable sources, also including aspects related to bioenergy and Cleaner Production. Thus, in the present study were molded briquettes using the powder of coffee grounds and wood sawdust in different proportions of these materials to evaluate mechanical properties of diametrical compression. Also analyzes were performed to determine the moisture, volatile matter and ash contents, besides the determination of the calorific value content (PCS). All compositions containing sawdust briquettes caused increases in mean values of maximum resistance properties diametrical compression and elastic modulus when compared to the values of these properties of briquettes molded only with the coffee grounds. The different composition of briquettes containing sawdust presented similar value of resistance to diametrical compression. Considering the calorific values (PCS), all samples showed similar results compared to the literature. The briquettes containing only coffee grounds in the composition presents results of ash, volatile contents and PCS similar to the samples containing sawdust. However, the briquettes containing only coffee grounds showed lower maximum compressive strength compared to all other also molded with sawdust briquettes.

Este trabalho envolveu a obtenção de filmes poliméricos a partir de amido de milho e incorporação de lignina na forma de lignossulfonato. A motivação deste trabalho está relacionada à utilização do amido na obtenção de filmes devido ao seu potencial de biodegradação, além do aproveitamento de resíduos de lignossulfonatos provenientes da indústria de celulose e papel. Para a obtenção dos filmes foram utilizados lignossulfonatos em pó e foram realizadas diversas moldagens com variação do tipo e da proporção (1% a 4%) de lignossulfonato utilizado. Algumas análises foram realizadas nos filmes poliméricos para comparar propriedades térmicas por DSC (Calorimetria Exploratória Diferencial), e propriedades de tração, em equipamento de DMTA (Análise Térmica Dinâmico-Mecânica). Neste estudo são destacadas as análises da biodegradação e da emissão dos gases liberados utilizando a técnica de Cromatografia Gasosa. De acordo com os resultados de DMTA, a maioria dos filmes poliméricos contendo lignossulfonatos apresentou resistência à tração inferior quando comparados aos filmes poliméricos sem lignossulfonatos (1,024 MPa). Porém, os filmes contendo lignossulfonato modificado com sódio (Vixil S) apresentaram maiores valores de resistência à tração quando comparado aos outros filmes contendo os lignossulfonatos utilizados (Vixil I e Vixil Tan). Nas análises térmicas foram notadas semelhanças entre os dois tipos principais de filmes poliméricos (amido; e amido com lignossulfonato), com alguns deslocamentos das temperaturas dos principais picos máximos dos filmes contendo lignossulfonato (4%, Vixil S). Na análise de biodegradabilidade foi verificado que os materiais são biodegradáveis e houve uma emissão maior de CO2 e N2O das amostras dos filmes contendo 4% lignossulfonato do tipo Vixil S, em comparação com as amostras sem lignossulfonato.

We obtained polymer films from corn starch with lignin incorporation as lignosulfonate. The motivation is the use of starch in obtaining films, due to their potential for biodegradation, and the use of lignosulfonate waste from the pulp and paper industry. To obtain films of lignosulfonates various powders of lignosulfonate were used, varying type and proportion (1% to 4%). Analyses were performed on polymer films to compare thermal properties by Differential Scanning Calorimetry, and tensile properties in Dynamic Mechanical Thermal Analysis, DMTA. We emphasize analyses of biodegradation and gas emission using gas chromatography. According to the results of DMTA, most polymeric films containing lignosulfonates showed lower tensile strength when compared to polymer films without lignosulfonates (1.024 MPa). However, the films containing lignosulfonate modified with sodium (Vixil S) showed higher tensile strength when compared to other films containing lignosulfonates (Vixil I and Vixil Tan). With some displacement of the main maximum peak temperatures for the films containing lignosulfonate (4% Vixil S), thermal analysis similarities between the two main types of polymer films (starch and starch with lignosulfonate) were observed. All materials are biodegradable, but higher CO2 and N2O emissions were observed for samples of the films containing 4% lignosulfonate type, Vixil S, compared to the samples without lignosulfonate.

Carbon fiber reinforced composites (CFRC) have been used in aeronautical industry in the manufacture of different aircraft components that must attend tight mechanical requirements. This paper shows a study involving mechanical (flexural, shear, tensile and compressive tests) and morphological characterizations of four different laminates based on 2 epoxy resin systems (8552TM and F584TM) and 2 carbon fiber fabric reinforcements (Plain Weave (PW) and Eight Harness Satin (8HS)). All laminates were obtained by handing lay-up of prepregs plies (0º/90º) and consolidation in an autoclave following an appropriate curing cycle with vacuum and pressure. The results show that the F584-epoxy matrix laminates present better mechanical properties in the tensile and compressive tests than 8552 composites. It is also observed that PW laminates for both matrices show better flexural and interlaminar shear properties.

Carbon fabric/epoxy composites are materials used in aeronautical industry to manufacture several components as flaps, aileron, landing-gear doors and others. To evaluate these materials become important to know their mechanical properties, for example, the tensile strength. Tensile tests are usually performed in aeronautical industry to determinate tensile property data for material specifications, quality assurance and structural analysis. For this work, it was manufactured four different laminate families (F155/PW, F155/HS, F584/PW and F584/HS) using pre-impregnated materials (prepregs) based on F155TM and F584TM epoxy resins reinforced with carbon fiber fabric styles Plain Weave (PW) and Eight Harness Satin (8HS). The matrix F155TM code is an epoxy resin type DGEBA (diglycidil ether of bisphenol A) that contains a curing agent and the F584TM code is a modified epoxy resin type. The laminates were obtained by handing lay-up process following an appropriate curing cycle in autoclave. The samples were evaluated by tensile tests according to the ASTM D3039. The F584/PW laminates presented the highest values of tensile strength. However, the highest modulus results were determined for the 8HS composite laminates. The correlation of these results emphasizes the importance of the adequate combination of the polymeric matrix and the reinforcement arrangement in the structural composite manufacture. The microscopic analyses of the tested specimens show valid failure modes for composites used in aeronautical industry.

Carbon/epoxy 8552 prepreg is a thermoplastic toughened high-performance epoxy being used in the manufacture of advanced army material. Understanding the cure behavior of a thermosetting system is essential in the development and optimization of composite fabrication processes. The cure kinetics and rheological behavior were evaluated using a differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and a rheometer. Values of the kinetic parameters were obtained from dynamic DSC scans using an nth order reaction model. Rheological measurements as a function of temperature and time were made for the prepreg system. The manufacturer's recommended cure cycle was evaluated and considered adequate to consolidated the studied system.

Four families of carbon fiber reinforced composites (CFRC) used in aeronautical industry were evaluated by flexural and interlaminar shear tests. It is also characterized three families of non-conditioned and conditioned CFRC by compression test. The composites were obtained by hand lay-up process in autoclave by using prepregs based on epoxy matrices (F155 and F584) and carbon fiber fabric reinforcements (PW-"Plain Weave" and 8HS-"Eight Harness Satin"). The F155-epoxy matrix was cured at 121 °C and the F584-epoxy type at 177 °C. After molding, the laminates were cut in specimens attending the ASTM D790 for the flexural test, the ASTM D2344 for the interlaminar shear test (ILSS) and the ASTM D3410 for the compressive test. The compressive tests were performed for testing the specimens before and after hygrothermal conditioning. The results show that the F584-epoxy matrix laminates present higher mechanical properties when compared to the F155-epoxy ones. The shear-tested samples observed by scanning electron microscopy and that ones tested in flexural, analyzed by stereoscopy, revealed that the fractured surfaces present typical aspects. The compressive results show that the hygrothermal conditioning caused the decrease of the compressive strength in, approximately, 8-20% depending on the laminate type. The failure modes of the tested specimens were evaluated showing good agreement with the literature.

Thermoplastic composites have been applied in a wide variety of industrial products, showing recently a great potential to be used in aeronautical field. The objectives of this work were to evaluate the fiber/matrix interface of carbon fiber reinforced polypropylene-based matrices after tensile and impact tests and also to compare the mechanical test results of the manufactured laminates. The laminates were prepared by stacking carbon fiber fabric style Plain Weave (CF) and films of four different polypropylene matrices, described as (a) polypropylene-PP, (b) polypropylene-polyethylene copolymer-PP-PE, (c) PP-PE with an interfacial compatibilizer-AM1 and (d) PP-PE containing an elastomeric modifier-AM2. The composites were processed using hot compression molding. The mechanical testing results showed that the CF-AM1 laminate family presented the lowest impact strength and the highest tensile strength values when compared to the other laminates. SEM analysis observations of both tensile and impact fractured specimens of the CF-PP/PE-AM1 specimens revealed a stronger fiber/matrix interface. The CF-PP/PE-AM2 laminate showed a lower tensile strength and higher impact strength values when compared to the CF-PP/PE-AM1 one. PP-PE and PP laminates presented the lowest impact strength values.