Viabilidade de utilização de um compósito a partir de resíduos para a construção de casas populares

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Composito de poliuretano de mamona e residuo industrial para isolacao termica e absorcao sonora

This work proposes the development of an innovative material made from a vegetable polyurethane matrix and load of industrial waste, from retread tires, for thermal insulation and environmental comfort. Experimental procedures are presented, as well as the results of the thermal and acoustic performance of this composite material, made from an expansive foam derived from the castor seed oil and fiber of scrap tires. The residue was treated superficially with sodium hydroxide, to eliminate contaminants, and characterized macroscopically and microscopically. Samples were produced with addition of residues at levels of 5%, 10%, 15% and 20% by weight, for determination of thermal properties: conductivity, heat capacity and thermal diffusivity, sound absortion index and density. The results were compared to commercially available thermal insulation and sound absorbing products. According to the analysis of results, it was concluded that the developed composite presents characteristics that qualify it as a thermal insulation with superior performance, compared to commercial available insulation, and sound absorption capacity greater than the castor oil polyurethane s, without addition of the residue

Estudo das propriedades mecânicas de biocompósitos de polipropileno reforçados com fibras naturais

This research presents an approach to the addition of curauá fibers and licuri fibers in a polypropylene resin matrix, such as an alternative proposal to reinforce the polymeric composites. Fiber content of 0 %, 5 %, 10 %, and 20% were analyzed for verification of their mechanical properties comparing them, inclusive with the properties of polypropylene. The grainulated biocomposites had been prepared in an extrusora. The test bodies had been molded by injection and submitted to the mechanical essays uniaxial traction, flexion on three points, impact, in addition to thermal tests (HDT). These biocomposites had been also subjected the essay physicist-chemistry index of fluidity (IF). It was observed that the biocomposites of PP with 20% curauá, obtained bigger increase in the modulus of elasticity and a bigger reduction in the resistance to the impact. In the mechanical behavior, for all the biocomposites, these were increases in values of the limit of drainage and tension of rupture, when tested by uniaxial traction, as they added the fibers. Another important point was the increase of the resistance the flexion. It was also noted that the addition of fibers reduced the thermal degradation of the mixture natural fibers / polypropylene.

Desenvolvimento de um laminado compósito híbrido a base de fibras de vidro/licurí

This research work is based, in search of reinforcement s vegetable alternative to polymer composites. The idealization of making a hybrid composite reinforced with vegetable fibers licuri with synthetic fibers is a pioneer in this area. Thus was conceived a hybrid composite laminate consisting of 05 (five) layers being 03 (three) webs of synthetic fibers of glass and E-02 (two) unidirectional fabrics of vegetable fibers licuri. In the configuration of the laminate layers have alternating distribution. The composite laminate was manufactured in Tecniplas Commerce & Industry LTD, in the form of a card through the manufacturing process of hand lay up. Licuri fibers used in making the foil were the City of Mare Island in the state of Bahia. After cooking and the idealization of the hybrid composite laminate, the objective of this research work has focused on evaluating the performance of the mechanical properties (ultimate strength, stiffness and elongation at break) through uniaxial tensile tests and three point bending. Comparative studies of the mechanical properties and as well as among other types of laminated hybrid composites studied previously, were performed. Promising results were found with respect to the mechanical properties of strength and stiffness to the hybridization process idealized here. To complement the entire study were analyzed in terms of macroscopic and microscopic characteristics of the fracture for all tests.

Estudo da flamabilidade e resistência à chama de compósito de poliéster insaturado e fibra da folha do abacaxizeiro (PALF)

In the present research work, composites were prepared using pine apple leaf fibres (PALF) as reinforcement with unsaturated polyester resin as matrix, incorporating with fire retardant at different compositions. The PALF was obtained from the decortication of pine apple leaves obtained from Ramada 4 from Ielmo Marinho in the State of Rio Grande do Norte. The unsaturated polyester resin and the catalyzer were bought from the local establishment. The fire retardant, aluminium tri-hydroxide - Al(OH)3 was donated by Alcoa Alumínio S.A and was used in the proportions of 20%, 40% and 60% w/w. Initially the fibres were treated with 2% NaOH for 1 hour, to remove any impurities present on the fibre surface, such as wax, fat, pectin and pectate, in order to have a better adsorption of the fibres with the matrix as well as the flame retardant. The fibre mat was prepared in a mat preparator by immersion, developed in the Textile Engineering Laboratory, at the UFRN. The composites (300x300x3 mm) were prepared by compression molding and the samples (150x25x3 mm) for analysis of the properties were cut randomly using a laser cutter. Some of the cut samples were used to measure the smoke emission and fire resistance using UL94 standard. Mechanical tension-extension and flexural properties were carried in CTGás RN and the Laboratório de Metais e Ensaios Mecânicos Engenharia de Materiais UFRN , as well as SEM studies were carried out at Núcleo de Estudos em Petróleo e Gás Natural - UFRN . From the observed results, it was noted that, there was no marked influence of the fire retardant on the mechanical properties. Also in the water absorption test, the quantity of water absorbed was less in the sample with higher concentration of fire retardant. It was also observed that the increase in the proportion of the fire retardant increased the time of burning, may be due to the compactness of the composite due to the presence of fire retardant as a filling material even though it was meant to reduce the rate of inflammability of the composite

Compósito para fabricação de blocos para construção de casas: estudos térmico e de materiais

We present two models of blocks made of composite material obtained from the use of cement, plaster, EPS crushed, shredded tire, mud, sand and water, for the construction of popular housing. Were made metal molds for the manufacture of blocks to be used in the construction of a residence for low-income families. Performed tests of compressive strength of the composite for various formulations that met the specific standard for blocks used in construction. To study the thermal conductivity of the composite for further study of thermal comfort generated in a residence built with the proposed composite. We also determined the mass-specific and water absorption for each formulation studied. Using a home already built with another composite material, made up the closing of a window with the building blocks and found the thermal insulation, measuring external and internal temperatures of the blocks. The blocks had made good thermal insulation of the environment, resulting in differences of up to 12.6°C between the outer and inner faces. It will be shown the feasibility of using composite for the end proposed and chosen the most appropriate wording

Desenvolvimento e análise de material compósito a base de penas de frango (fibras de queratina-KF) e matriz de poliéster insaturado

Use of natural fibres as a reinforcement material in the manufacture of composites show a series of advantages: availability, biodegradability, low weight and regeneration in relation to synthetic fibres, thus justifying its utilization. In the present research work, composites were developed with chicken feathers (KF), using unsaturated polyester resin as matrix, for diversified applications, mainly in the furniture/timber industry.At present, in Brazil the chicken feathers are used as part of the animal feed, even though this material possesses low aggregated value. The chicken feathers are hollow, light and resistant. After washing with water at room temperature, a part of the chicken feathers were treated with 2% NaOH. Composites were manufactured using treated and untreated chicken feathers with unsaturated orthothalic polyester resin and 1% peroxide as catalyser, obtained in the commerce. Samples with size 150x25x3 mm for mechanical tests were cut by laser in the composite plate. Mechanical analyses were carried out in the Laboratório de Metais e Ensaios Mecânicos UFRN. All the analyses were in accordance with ASTM standards. SEM analyses were also carried out on the samples.In the analyses of the results obtained, it was observed that the composites made with untreated chicken feathers showed better results (Traction 11.406 MPa and 9.107 MPa Bending 34.947 and 20.918 MPa for samples with and without treatment respectively) compared to the composite with treated feathers. Very low values of the water absorption results, evidenced the impermeability characteristic of the feathers. From the SEM images, the structure, fracture and the fibre/matrix adsorption can be evidenced. In the flammability test, it was observed that despite the feathers having sulfur as a constituent, natural inhibitor of flame, no burning support of the composites, because the manufacturing process of the composite

Viabilidade de utilização de um compósito de matriz cerâmica com cargas recicláveis na fabricação de equipamentos solares

Composite materials can be defined as materials formed from two or more constituents with different compositions, structures and properties, which are separated by an interface. The main objective in producing composites is to combine different materials to produce a single device with superior properties to the component unit. The present study used a composite consisting of plaster, cement, EPS, tire, PET and water to build prototype solar attempt to reduce the manufacturing cost of such equipment. It was built two box type solar cookers, a cooler to be cooled by solar energy, a solar dryer and a solar cooker concentration. For these prototypes were discussed the processes of construction and assembly, determination of thermal and mechanical properties, and raising the performance of such solar systems. Were also determined the proportions of the constituents of the composite materials according to specific performance of each prototype designed. This compound proved to be feasible for the manufacture of such equipment, low cost and easy manufacturing and assembly processes

Compósito reforçado com sisal para aplicação na moda

The objective of this research is the fabrication of a composite reinforced with dyed sisal fiber and polyester matrix for application in the fields such as, fashion, clothing, interior textiles; fashion accessories are some of the examples. For the fabrication of the composite, the sisal fibers were subjected to processes such as: chemical treatment with sodium hydroxide (NaOH) in the removal of impurities; bleaching for removing the yellowish color of the natural fiber and dyeing with direct dyes to confer the colors blue, green and orange. The search for new technologies ecologically correct has become a major concern in recent decades. Studies show that composite polymer reinforced by natural fibers is suitable for a large number of applications, and its use is advantageous in terms of economic and ecological. The dyed fibers were cut to a length of 30 mm, is used in the confection of webs. For this purpose, a web preparer by immersion, developed in the Laboratory of Chemical Textile of UFRN. The composite sheets measuring 300 x 300 x3 mm were molded by compression, with unsaturated orthophthalic polyester as matrix, and the samples in sizes 150 x 25 x 3 mm were cut with the aid of a laser machine, to be subjected to traction and flexion. The mechanical properties of traction and flexion in three points were performed in the Laboratory of metal and mechanical tests of Materials Engineering of UFRN. The resulting samples from the tests were evaluated in scanning electron microscope (SEM) at CTGas RN. On the basis of the analysis of the results from the mechanical tests, it was observed that the composite had good mechanical behavior, both in traction as in flexion. Furthermore, it was observed that in the water absorption test, the samples had a different percentage among themselves, this occurred due to the variation of density found in the fibre webs. The images of the SEM showed the failures from the manufacturing process and the adhesion of fibre/matrix. When the samples were prepared with the dyed fibers to be applied in fashion, the results were positive, and it can be concluded that the main objective of this work was achieved

Resposta térmica de um compósito PEEK+PTFE+Fibra de carbono+grafite

Composites based on PEEK + PTFE + CARBON FIBER + Graphite (G_CFRP) has increased application in the top industries, as Aerospace, Aeronautical, Petroleum, Biomedical, Mechanical and Electronics Engineering challenges. A commercially available G_CFRP was warmed up to three different levels of thermal energy to identify the main damage mechanisms and some evidences for their intrinsic transitions. An experimental test rig for systematize a heat flux was developed in this dissertation, based on the Joule Effect. It was built using an isothermal container, an internal heat source and a real-time measurement system for test a sample by time. A standard conical-cylindrical tip was inserted into a soldering iron, commercially available and identified by three different levels of nominal electrical power, 40W (manufacturer A), 40W (manufacturer B), 100W and 150W, selected after screening tests: these power levels for the heat source, after one hour of heating and one hour of cooling in situ, carried out three different zones of degradation in the composite surface. The bench was instrumented with twelve thermocouples, a wattmeter and a video camera. The twelve specimens tested suffered different degradation mechanisms, analyzed by DSC (Differential Scanning Calorimetry) and TG (Thermogravimetry) techniques, Scanning Electron Microscopy (SEM) and Energy-Dispersive X-Rays (EDX) Analysis. Before and after each testing, it was measured the hardness of the sample by HRM (Hardness Rockwell M). Excellent correlations (R2=1) were obtained in the plots of the evaporated area after one hour of heating and one hour of cooling in situ versus (1) the respective power of heat source and (2) the central temperature of the sample. However, as resulting of the differential degradation of G_CFRP and their anisotropy, confirmed by their variable thermal properties, viscoelastic and plastic properties, there were both linear and non-linear behaviour between the temperature field and Rockwell M hardness measured in the radial and circumferential directions of the samples. Some morphological features of the damaged zones are presented and discussed, as, for example, the crazing and skeletonization mechanism of G_CFRP

Fabricação de eco-composito com a fibra de lã canina

The Sustainability has been evidence in the world today; organizations have sought to be more and more into this philosophy in their processes, whether products or attendance. In the present work were manufactured eco-composites with animal fiber (dog wool) that is currently discarded into the environment without any use. The fibers were characterized and made matting (non-woven). The phases of the project were consisted to develop methods and to convert these fibers (booster) blended with polyester resin (matrix) in different proportions (10%, 20% and 30%) at the composite. Were studied fiber characteristics, mechanical properties of the composites, water absorption and scanning electron microscopy. Initially, the fibers were treated with solution of sodium hydroxide of 0.05 mols, and then taken to matting preparing at the textile engineering laboratory - UFRN. The composites were made by compression molding, using an orthophthalic polyester resin as matrix and 1% MEK (methyl ethyl ketone peroxide) as initiator (catalyst). To evaluate the mechanical tests (tensile and flexural) and water absorption were made twelve specimens with dimensions 150x25x3 mm were cut randomly. According to the standard method, tensile tests (ASTM 3039) bending tests (ASTM D790) were performed at the mechanical testing of metals at laboratory UFRN. The results of these tests showed that the composite reinforced with 30% had a better behavior when exposed to tension charge; while on the three points bending test showed that the composite reinforced with 10% had a better behavior. In the water absorption test it was possible to see that the highest absorption happened on the composite reinforced with 30%. In the micrographs, it was possible to see the regions of rupture and behavior of the composite (booster / matrix)

Compósito Polimérico Híbrido: Comportamento Mecãnico, Descotinuidade Geométrica e Resistência Residual

The growing demand in the use of hybrid composite materials makes it essential a better understanding of their behavior face of various design conditions, such as the presence of geometric discontinuities in the cross section of structural elements. This way, the purpose of this dissertation is a study of the mechanical response (strength and stiffness), modes (characteristics) of fracture and Residual Strength of an hybrid polymeric composite with and without a geometric discontinuity in its longitudinal section (with a reduction in the cross section) loaded by uniaxial tension. This geometric discontinuity is characterized by central holes of different diameters. The hybrid composite was fabricated as laminate (plate) and consisting of ortho-tereftalic polyester matrix reinforced by 04 outer layers of Jute fibers bidirectional fabrics and 01 central layer of E-glass bidirectional fabric. The laminate was industrially manufactured (Tecniplas Nordeste Indústria e Comércio Ltda.), obtained by the hand lay-up technique. Initially, a study of the volumetric density of the laminate was made in order to verify its use in lightweight structures. Also were performed comparative studies on the mechanical properties and fracture modes under the conditions of the specimens without the central hole and with the different holes. For evaluating the possible influence of the holes in the structural stability of the laminate, the Residual Strength of the composite was determined for each case of variation in hole diameter. As a complementary study, analyses of the macroscopic final fracture characteristic of the laminates were developed. The presence of the central hole of any sizes, negatively changed the ultimate tensile strength. Regarding the elastic modulus, moreover, the difference found between the specimens was within the range of tests displacement, showing the laminate stability related to the stiffness

Morfologia e propriedades mecânicas da fibra de sisal unidirecional e em sobreposição de compósito com resina epóxi

The composites manufactured with long fibres aligned in a single direction, and overlay has been shown to have better performance than the short fibers randomly distributed. In particular, the lignocellulosic fibers extracted from the sisal leaves, used in conjunction with the epoxy resin has attracted the attention of many researchers because the final properties of the system formed. In this work composites based on epoxy resin reinforced with sisal fibers were manufactured. The sisal fibres were treated with an alkaline solution of 0.06 mol/l NaOH. The treated, and untreated fibres were subjected to tension x extension tests. The composites were manufactured in the "Lossy" mold with the specifications of the samples to be produced (300x20x4 mm). The tension tests were carried out in accordance with the ASTM standards 3039 (for the composite aligned in a single direction) and ASTM D5573 (for composites in overlay), three point bending tests were performed according to ASTM D790. Analyzing the results of the tests of tension and three point bending tests, it was observed that the composites with the configuration of overlapping had the better elastic module in both tests. As to the maximum resistance to tension, the best result was the composites aligned in a single direction. Tests of absorption of water and micrographs are in progress

Obtenção e caracterização de um compósito de poliuretano de mamona e pó de vidro para aplicações em insolantes térmicos

Thermal insulation is used to protect the heated or cooled surfaces by the low thermal conductivity materials. The rigid ricin polyurethane foams (PURM) are used for thermal insulation and depend on the type and concentration of blowing agent. Obtaining PURM occurs by the use of polyol, silicone, catalyst and blowing agent are pre -mixed, reacting with the isocyanate. The glass is reusable, returnable and recyclable heat insulating material, whose time of heat dissipation determines the degree of relaxation of its structure; and viscosity determines the conditions for fusion, operating temperatures, annealing, etc. The production of PURM composites with waste glass powder (PV) represents economical and renewable actions of manufacturing of thermal insulating materials. Based on these aspects, the study aimed to produce and characterize the PURM composites with PV, whose the mass percentages were 5, 10, 20, 30, 40 and 50 wt%. PURM was obtained commercially, while the PV was recycled from the tailings of the stoning process of a glassmaking; when the refining process was applied to obtain micrometer particles. The PURM + PV composites were studied taking into account the standard sample of pure PURM and the influence of the percentage of PV in this PURM matrix. The results of the chemical, physical and morphological characterization were discussed taking into account the difference in the microstructural morphology of the PURM+PV composites and the pure PURM, as well the results of the physicochemical, mechanical e thermophysical tests by values obtained of density, hardness, compressive strength, specific heat, thermal conductivity and diffusivity. In general, the structure of pure PURM showed large, elongated and regular pores, while PURM+PV composites showed irregular, small and rounded pores with shapeless cells. This may have contributed to reducing their mechanical strength, especially for PURM - PV50. The hardness and density were found to have a proportional relationship with the PV content on PURM matrix. The specific heat, thermal diffusivity and thermal conductivity showed proportional relationship to each other. So, this has been realized that the increasing the PV content on PURM matrix resulted in the rise of diffusivity and thermal conductivity and the decrease of the specific heat. However, the values obtained by the PURM composites were similar the values of pure PURM, mainly the PURM-PV5 and PURM-PV10. Therefore, these composites can be applied like thermal insulator; furthermore, their use could reduce the production costs and to preserve the environment

Tubulações de PRFV com adição de areia quartzosa visando sua aplicação na indústria do petróleo

Fillers are often added in composites to enhance performance and/or to reduce cost. Fiberglass pipes must meet performance requirements and industrial sand is frequently added for the pipe to be cost competitive. The sand is added to increase pipe wall thickness, thus increase pipe stiffness. The main goal of the present work is to conduct an experimental investigation between pipes fabricated with and without de addition of sand, to be used in the petroleum industry. Pipes were built using E-glass fibers, polyester resin and siliceous sand. The fabrication process used hand lay up and filament winding and was divided in two different parts: the liner and the structural wall. All tested pipes had the same liner, but different structural wall composition, which is the layer where siliceous sand may be added or not. The comparative investigation was developed considering the results of longitudinal tensile tests, hoop tensile tests, hydrostatic pressure leak tests and parallel-plate loading stiffness tests. SEM was used to analyze if the sand caused any damage to the glass fibers, during the fabrication process, because of the fiber-sand contact. The procedure was also used to verify the composite conditions after the hydrostatic pressure leak test. The results proved that the addition of siliceous sand reduced the leak pressure in about 17 %. In the other hand, this loss in pressure was compensated by a stiffness increment of more than 380 %. MEV analyses show that it is possible to find damage on the fiber-sand contact, but on a very small amount. On most cases, the contact occurs without damage evidences. In summary, the addition of sand filler represented a 27.8 % of cost reduction, when compared to a pipe designed with glass fiber and resin only. This cost reduction combined to the good mechanical tests results make siliceous sand filler suitable for fiberglass pressure pipes