Desenvolvimento de um painel sanduíche com carga de particulado oriundo de resíduo lignocelulósico para aplicação em produtos na área de equipamentos de proteção

This work aims to study and investigate the use of a hybrid composite polymer formed with blanket aramid (Kevlar 29) fiber blanket flax fiber and particulate dry endocarp of coconut (Cocos nucifera Linn), using as matrix an epoxy resin based thermoset for use in areas of protective equipment. Besides such material is used an aluminum plate, joined to the composite by means of glue based on epoxy and araldite commercial. The manufacturing process adopted was manual lamination (Hand Lay Up) to manufacture the hybrid composite. After the composite is prepared, an aluminum plate is subjected to pressure and glued to cure the adhesive. Layers of veil will also be used to separate the particulate from the linen blanket layer without disturbing the alignment of the fibers of the blankets. To characterize the mechanical and physical behavior was manufactured a plate of 800 x 600 mm of the hybrid composite, which were removed specimens for tests of water absorption to saturation; density; impact test (Charpy) and two test specimens for ballistic testing 220 mm x 200 mm to make a comparative study between the dry state and saturated water absorption and thus see the ballistic performance of these two conditions. The test was applied to make a comparative study of fracture in these two conditions, caused by penetrating ballistic missile (38 and 380). To test the impact (Charpy) will analyze the absorbed energy, fracture appearance and lateral contraction, also in dry condition and saturation of absorbed water, thereby analyzing situations where the impact load is relevant, such as bumps and shocks produced by stone, metal or wooden bars among others. The proposed configuration, along with the tests, has the purpose, application in the fields of equipment against ballistic impact, such as helmets; bullet proof vests; shields; protective packaging and other items to be identified in this research.

Influência da absorção de umidade no comportamento mecânico nos compósitos poliméricos híbridos Kevlar/vidro quando imerso em água do mar e petróleo

The polymer matrix composite materials are being used on a large scale in the most different industrial fields such as aerospace, automotive, oil, among others, since the industrial perspectives is currently working with materials which have a good mechanical performance at high service life and cost / benefit. Thus, the determination of the mechanical properties is indispensable for the characterization of waste resulting in greater expansion of this type of material. Thus, this work will be obtained three plates laminated with tereftálica polymeric matrix reinforced by a bidirectional woven E-glass and kevlar both industrially made, where the plates are manufactured by manual lamination process (hand lay-up), all laminates have five enhancement layers, the first hybrid laminate will consist of bidirectional woven E-glass fiber, kevlar fiber interspersed with layers, is formed by the second bidirectional woven kevlar fiber at the ends of the laminate (two layers), and in the center the glass fiber fabric (three layers), the third plate is composed of only the bidirectional woven E-glass fiber. Then were prepared specimens (CP) by standard, to determine the mechanical properties of tensile and bending in three points. After fabrication of the specimens, they were immersed in oil and seawater. After that, there was a comparison of the mechanical properties for the test condition in the dry state. Showing that there was a considerable increase in the properties studied because the effect of hybridization in laminates.

Compósitos poliméricos a base de fibras de licuri: efeitos da hibridização e do envelhecimento ambiental acelerado

The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property