Per: Belayne Zanini Marchi (ime/rj), Ary Machado de Azevedo (ime/rj), Jean Carlos Carelo (COPPE/ RJ), Sérgio Neves Monteiro (IME/RJ), ANDRÉ BEN-HUR DA SILVA FIGUEIREDO (IME/RJ)
Abstract:
The use of cellulosic or natural fibers (NLFs) in composites is considered a promising alternative due to their low cost, renewability, biodegradability, and low specific weight. Recognized for their high mechanical properties, these fibers have become widely used in various technological sectors, especially in engineering. However, lesser-known natural fibers that are not mentioned in reviews still require research to evaluate their potential as reinforcement in composites, such as ubim fiber. Ubim is a small plant found in the undergrowth of forests with high rainfall rates in the states of Amazonas, Acre, Amapá, Pará, Maranhão, and Piauí. Thus, the thermal and mechanical properties, crucial for engineering applications involving temperature variations, were studied. This work investigated the dynamic-mechanical properties of epoxy matrix composites reinforced with 10%, 20%, and 30% ubim fiber using Dynamic Mechanical Analysis (DMA). The results showed that the incorporation of fibers resulted in higher values of storage modulus (E') and loss modulus (E”), as well as an increase in the glass transition temperature (Tg). Additionally, a lower damping factor (tan δ) was observed in composites with higher volumetric fractions of ubim fiber.