Resumo: A adição de cargas minerais a polímeros termoplásticos como o polipropileno (PP) esteve durante muito tempo relacionada à tentativa de redução de custos. Atualmente, com o desenvolvimento tecnológico da indústria e de novas aplicações, as cargas ganharam uma maior importância e passaram a atender mais que o objetivo econômico, por agregarem melhorias nas características físicas e químicas dos produtos. O trabalho baseia-se nessa visão e tem como objetivo a avaliação dos efeitos nas propriedades mecânicas dos compósitos formados por polipropileno (PP) e Carbonato de Cálcio (CaCO3) em concentrações de 5 e 10%. Os resultados demostram que a adição de CaCO3, proporciona uma diminuição na capacidade de deformação do compósito, confirmada pelo aumento no módulo de elasticidade e diminuição da deformação específica na ruptura, além de diminuição da resistência ao impacto. Sugere-se novas pesquisas utilizando nanopartículas de carbonato de cálcio para verificar o comportamento da matriz polimérico frente a elementos de menor tamanho.

The construction industry contributes enormously to the high levels of carbon dioxide on the planet. For this reason, the sector has been investing in the development of new products that reduce the environmental impact. This study developed a fibrous polymeric composite using industrial residues of polyethylene terephthalate (PET) fibers for application in civil construction as a cladding element. The thermal and morphological characterization of the fiber was performed using Thermogravimetry (TG) and Scanning Electron Microscopy (SEM). Composites with 1, 3, and 5% PET fibers were obtained. Mechanical, morphological properties, chemical resistance, the effect of ultraviolet radiation and water absorption of the composites were evaluated. The results were compared to parameters established by the Brazilian standard NBR 15.575-3. Fibers had a smooth surface but with small surface defects, diameter between 20 and 30 µm and thermal stability up to 325.44 °C. The addition of 5% PET fibers resulted in an increase of more than 300% in the impact resistance of the composites, but with a reduction in the flexural strength. The mechanical and chemical resistance results met the parameters established by the standard used in the study. The degradation chamber test indicated that PET fibers suffered more from exposure to ultraviolet radiation than the polymeric matrix.

Fiber-reinforced composites represent 75% of the application of these materials in several industrial segments. It has the purpose of improving technical characteristics and reducing environmental impact through the use of sustainable raw materials such as natural fibers and other fibers from industrial waste. In this sense, the objective of this work was to study and compare the mechanical properties of polyester composites (PL) reinforced with natural sisal fiber and residues of polyethylene terephthalate (PET) synthetic fibers. Initially, we evaluated the moisture and morphology of the fibers. The composites with PL matrix were obtained and the fiber concentration varied by 1%, 3%, and 5% by weight. In the composites, the mechanical properties under flexion and impact resistance were evaluated. We concluded that the level of reinforcement with sisal fibers did not significantly affect the mechanical properties. However, the PET fiber provided significant improvements in the properties of the composite. Thus, the composites reinforced with PET fiber residue have advantages in the development of new material with sustainable characteristics.

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