Jane Maria Faulstich de Paiva

Mechanical and morphological characterizations of carbon fiber fabric reinforced epoxy composites used in aeronautical field

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.

A study on the environmental aspects of WEEE plastic recycling in a Brazilian company

PurposeThe high consumption of electrical and electronic equipment motivated by the rapid technological advances seen over the years has lead to an increase in the generation of waste electrical and electronic equipment (WEEE). Such residues contain various dangerous substances and therefore deserve special attention. To that end, the Brazilian Policy on Solid Waste has provided guidelines on integrated and solid waste management, such as consumer electronics, aiming at their appropriate disposal and treatment through reverse logistics. In this context, the present work focuses on studying the recycling of some WEEE plastics.MethodsThis study was conducted using the methodological framework presented in the International Standard ISO 14040:2006 and aimed to determine the life cycle inventory (LCI) of a WEEE plastic recycling process in a company in Brazil. Having collected the data, it was possible to identify and quantify the environmental aspects caused by the recycling process of major plastics (acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS). The study was conducted in the only company in Brazil that operates WEEE plastic recycling in large scale.Results and discussionSome of the environmental aspects caused during the recycling process of the plastics under study were identified and quantified. As a result, besides presenting the inventory, it was also possible to determine a reduction in the consumption of energy and in CO2 emissions. When compared to the production of virgin ABS and HIPS, the recycling processes for such plastics showed a reduction in energy consumption by approximately 90% for both plastics and a reduction in CO2 emissions by approximately 84% for HIPS and 87% for ABS. The plastics recycled by the company retain over 90% of their virgin mechanical properties.ConclusionsThe study shows that recycling is highly relevant and that components present in WEEE received appropriate destination and treatment. Recycling avoids environmental impacts as it prevents WEEE from being disposed of in landfills and as the pellets of recycled plastics can re-enter the supply chain as raw materials. Considering the legislation in Brazil, the stage of collection/transport/treatment of WEEE conducted by the company under study presents strong indications of contributions to the environment, society, and economy of the country.

Life cycle assessment of a steam thermolysis process to recover carbon fibers from carbon fiber-reinforced polymer waste

PurposeCarbon fibers have been widely used in composite materials, such as carbon fiber-reinforced polymer (CFRP). Therefore, a considerable amount of CFRP waste has been generated. Different recycling technologies have been proposed to treat the CFRP waste and recover carbon fibers for reuse in other applications. This study aims to perform a life cycle assessment (LCA) to evaluate the environmental impacts of recycling carbon fibers from CFRP waste by steam thermolysis, which is a recycling process developed in France.MethodsThe LCA is performed by comparing a scenario where the CFRP waste is recycled by steam-thermolysis with other where the CFRP waste is directly disposed in landfill and incineration. The functional unit set for this study is 2xa0kg of composite. The inventory analysis is established for the different phases of the two scenarios considered in the study, such as the manufacturing phase, the recycling phase, and the end-of-life phase. The input and output flows associated with each elementary process are standardized to the functional unit. The life cycle impact assessment (LCIA) is performed using the SimaPro software and the Ecoinvent 3 database by the implementation of the CML-IA baseline LCIA method and the ILCD 2011 midpoint LCIA method.Results and discussionDespite that the addition of recycling phase produces non-negligible environmental impacts, the impact assessment shows that, overall, the scenario with recycling is less impactful on the environment than the scenario without recycling. The recycling of CFRP waste reduces between 25 and 30% of the impacts and requires about 25% less energy. The two LCIA methods used, CML-IA baseline and ILCD 2011 midpoint, lead to similar results, allowing the verification of the robustness and reliability of the LCIA results.ConclusionsThe recycling of composite materials with recovery of carbon fibers brings evident advantages from an environmental point of view. Although this study presents some limitations, the LCA conducted allows the evaluation of potential environmental impacts of steam thermolysis recycling process in comparison with a scenario where the composites are directly sent to final disposal. The proposed approach can be scaled up to be used in other life cycle assessments, such as in industrial scales, and furthermore to compare the steam thermolysis to other recycling processes.

Filmes poliméricos baseados em amido e lignossulfonatos: preparação, propriedades e avaliação da biodegradação

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.

Methodology for soil respirometric assays: Step by step and guidelines to measure fluxes of trace gases using microcosms

Graphical abstract

Fractographic and rheological characterizations of CF/PP-PE-copolymer composites tested in tensile

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 Films and Starch Compositions with Other Materials

Due to growing concern about the environment, the use of biodegradable polymeric materials has been studied in order to minimize the environmental impact caused by synthetic polymers. Among these materials can be detached polymeric films containing corn starch, with low cost and available worldwide. This paper exhibits some characteristics of the starch and summarizes studies in which the authors present some properties of polymeric materials containing starch, especially mechanical and barrier properties, permeability to water vapor and the use of

DESENVOLVIMENTO DE PONTO DE COLETA DE RESÍDUOS ELETROELETRÔNICOS

One of the biggest environmental problems faced by the society is related to the lack of suitable sites for the disposal of solid electronics waste in which there are in their composition hazardous and toxic substances to the environment and to the human health. The lack of awareness of a large part of the population regarding the need to conduct an environmentally friendly disposal of these residues is also part of the current reality. These facts which have been intensified by population growth, increased globalization and development of technological sectors, provide a greater focus on the creation of new sustainable policies. The National Policy of Solid Waste (PNRS) stimulated the development of projects related to solid waste management. According to the PNRS, the waste electrical and electronic equipment (WEEE) have the requirement of establishing the reverse logistics by the return of the product after the use of the consumer, for instance, by recycling processes. Yet, there are not enough points of collections and information available to begin the process of collection and proper disposal of WEEE, or agreements among governments, companies, cooperatives and consumers related to this compromise. Hence, this paper has involved the development of a prototype of WEEE collection point in partnership with the sustainable innovation center, Sinctronics. The concern for the prototype design, as well as the evaluation of the best location in the university environment and the media were essential to the collection point to become attractive and useful. The results obtained through observation and questionnaires showed that there has already been an environmental awareness at the university referring to the disposal of waste, however, until that moment, there were not na appropriate collection point and public awareness campaigns for the importance related to the proper disposal of WEEE and information regarding to the rehabilitation process of such waste in the production cycle.

Utilização de Resíduos de Borra de Café e Serragem na Moldagem de Briquetes e Avaliação de Propriedades

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.

ANALYSIS OF THE PRODUCTION PROCESS OF POLYMER FILMS USING THE METHODOLOGY OF CLEANER PRODUCTION

The current technological advance guides the actions that have contributed to the study and implementation of a structured environmental management within companies. Thereby, this article discusses the application of Cleaner Production Methodology in a company engaged in the business of flexible films in the region of Sorocaba, Sao Paulo, Brazil. The study aims to identify opportunities of improvements that might reduce the environmental impact. There were visits in the enterprise during the execution of the project in order to get quantitative and qualitative data, which supported the mapping and understanding of the productive process. The application of Cleaner Production has allowed the identification of improvements in the process, better use of raw material, reduction of water use and minimization of waste generation. In this case, it has been used an adapted transformation model to map the system. Opportunities for future improvements have been identified and classified into the strategic levels of the Cleaner Production; some of them are related to the progress in the use of raw materials, reduction of water leaks through the process in the pipes, change of raw material from nonrenewable to renewable source, performance of preventive maintenance, minimization of waste generation, use of regranulated material generated in the process, etc. Therefore, for futures studies, it may be accomplished the analysis of economic and technical feasibility of each proposal identified in this report