ABSTRACT Composite materials using vegetal fibers and industrial waste are being applied in different areas and structures, requiring, more and more, researches that highlight their characteristics. In this context, the study of manufacturing techniques becomes increasingly necessary in order to use the appropriate tools and obtain the best conditions of the materials. Thus, this article demonstrates the behavior of the materials, which used the polyester resin with ground paper residue to generate the two composites studied in this paper, Polyester/smaller paper (PO/ PME) and Polyester/large paper (PO/PMA). These two materials were molded by hot compression and subjected to manufacturing processes. Joinery equipment were chosen for the experimentation of cutting, drilling, screw insertion and sanding to analyze the performance of these composite materials. As a general result, it can be observed that the composites maintained their physical integrity, because the particles of the load remained well anchored in the matrix in the two composite materials tested, giving the finish an aspect without damages, cracks or imperfections after the operations. Therefore, it is concluded that the materials created can be submitted to the manufacturing techniques evaluated in this article, reinforcing previous studies that suggest its use in the development of products such as furniture, table tops, decorative objects and others. Thus, this study contributes to Designer has knowledge of the potential of the material and make the best use of it.

ABSTRACT Concerns for the environment are recurrent in our society, and research on low impact materials such as those produced from waste is an alternative. This work is based on the reuse of scrap paper and rice hulls aiming to increase the life cycle of these waste products and to find better destination. Composites with a volumetric filler content (dispersed phase) of 80% were produced via compression molding using polyurethane (PU) based on castor oil or polyester resin as matrix, in four distinct families: polyester/rice hulls, PU/rice hulls, polyester/paper and PU/paper. The following tests were performed: water sorption, contact angle, hardness, impact and tensile testing. Scanning electron microscopy (SEM) was used for fracture morphology study. Basic visual analysis showed greater void content for the rice hull composites, making them less aesthetically appealing compared to paper. It was observed in the case of PU matrix the filler greatly influenced the rigidity since this pure material was more flexible compared to pure polyester. Filler incorporation decreased tensile strength of the polyester matrix but significantly increased that of the PU matrix.

This study focuses on the use of waste cotton fiber from the textile industry to produce composites with unsaturated polyester and to evaluate the performance of glass (G) / cotton (C) fiber laminates, particularly their mechanical and dynamic mechanical properties. Distinct stacking sequences were studied but the overall fiber content was kept constant. In general, hybrid laminates exhibited intermediate mechanical properties compared to those of the pure laminates, and optimum performance was obtained when the glass fiber mats were placed on the surfaces of the composite. Furthermore, some hybrid laminates exhibited superior dynamic mechanical performance, even compared to the pure glass laminate. Lower tan delta peak height (related to better fiber-matrix interaction) values and higher Tg were reported for the [C/G/ G ¯]s and [G/C/ C ¯]s samples which, together with the [G/C/ G ¯]s sample, exhibited the best results for reinforcement effectiveness and loss modulus peak height. Therefore, it is found possible to partially replace the glass fiber by waste cotton fiber considering that the final product may be optimized for mechanical property, which requires glass fiber at the surface of the laminate, or for dynamic mechanical properties, that allows higher cotton fiber content.

Compósitos de PP/argila/PP-g-MA/erucamida contendo 5% (em peso) de argila montmorilonita organofílica (Cloisite 20A), 5 e 15% de PP-g-MA como agente compatibilizante e 0, 0,5% e 1% de cis-13-docosenamida (erucamida) como agente co-intercalante, foram preparados por intercalação no estado fundido. Concentrados de argila e compatibilizantes foram processados em misturador interno e em seguida diluídos com a matriz de polipropileno em extrusora de dupla rosca corrotacional. Os compósitos foram caracterizados através das propriedades mecânicas, difração de raios X e microscopia óptica. Os resultados indicaram o efeito reforçante da argila organofilizada. A presença de co-intercalante aumentou significativamente a distância interlamelar da argila em todos os compósitos, em geral, não afetando notavelmente o comportamento mecânico dos compósitos. Por microscopia óptica foi possível observar o efeito dispersivo do perfil de rosca utilizado, que promoveu a quebra dos aglomerados de argila.

PP/organoclay/PP-g-MA/erucamide composites with 5% commercial organo-montmorillonite (Cloisite 20A), 5 and 15% maleated polypropylene as compatibilizer, and 0, 0.5 and 1% erucamide as a co-intercalating agent were prepared by melt intercalation. A masterbatch of compatibilizer and organoclay was compounded in an internal mixer and then diluted in the polypropylene matrix in a corotating twin-screw extruder. The compounds were characterized by x-ray diffraction, optical microscopy and mechanical properties. Results indicate that the organoclay acted as a reinforcer. Addition of the co-intercalating agent significantly increased the interlayer spacing of the clay, without notably affecting the mechanical behavior of the composites. Optical microscopy showed the dispersive effect of the screw profile used, which promoted the breaking of clay agglomerates.