Marchi Belayne Zanini, da Silveira Pedro Henrique Poubel Mendonça, Almeida Bezerra Wendell Bruno, da Silva Marcelo Henrique Prado, Monteiro Sergio Neves, da Silva Figueiredo André Ben-Hur
Department of Materials Science, Military Institute of Engineering-IME, Praça General Tibúrcio, 80, Praia Vermelha, Urca, RJ, 22290-270, Brazil.
Federal University of Cariri-UFCA, Science and Technology Center, Avenida Tenente Raimundo Rocha, 1639, Cidade Universitária, Juazeiro do Norte, CE, 63048-080, Brazil.
Sci Rep. 2024 Nov 4;14(1):26565. doi: 10.1038/s41598-024-78449-5.
Natural lignocellulosic fibers (NLFs) have shown a great potential as reinforcements in composites in recent decades. Among other reasons, environmental concerns and the depletion of oil reserves justify research on natural composites as they offer an environmentally friendly alternative and align with the principles of sustainable development. Among the plethora of NLFs available in nature, the ubim fiber (Geonoma baculifera) has not yet been investigated as a reinforcement for composites in potential engineering applications. Therefore, this study evaluates, for the first time, the mechanical properties of epoxy composites with 10, 20, and 30 vol% of ubim fibers. These properties were assessed through Izod impact, tensile and flexural tests as well as dynamic mechanical analysis (DMA). The data were statistically analyzed using the ANOVA method. Scanning electron microscopy (SEM) analysis indicated a transition from a purely brittle fracture mechanism to a ductile-brittle combination as the fiber volume in the composite increased. Tensile tests of the composites demonstrated an increasing trend in strength and elastic modulus with fiber volume. The results of the flexural tests also displayed a similar trend in strength and elasticity modulus for the composites. The results of DMA tests showed that composite materials with a 30 vol% of ubim fibers exhibited a high glass transition temperature and a low tan δ value, suggesting higher stiffness of this composite compared to others. Overall, the results indicated that the incorporation of 30 vol% ubim fibers into the composites significantly improved their mechanical properties compared to other tested fiber fractions. Additionally, their functional characteristics, such as simplicity in the manufacturing process, low cost, and excellent strength-to-weight ratio, make these composites particularly suitable for applications in sectors such as the automotive industry, construction panels, and packaging. These factors contribute to the development of an efficient, sustainable, recyclable and environmentally friendly composite.
近几十年来，天然木质纤维素纤维（NLFs）在复合材料增强方面展现出巨大潜力。除其他原因外，环境问题和石油储备的枯竭使得对天然复合材料的研究具有合理性，因为它们提供了一种环保替代方案，符合可持续发展原则。在自然界中大量存在的NLFs中，乌比姆纤维（Geonoma baculifera）尚未作为潜在工程应用中复合材料的增强材料进行研究。因此，本研究首次评估了含有10%、20%和30%体积分数乌比姆纤维的环氧复合材料的力学性能。这些性能通过悬臂梁冲击、拉伸和弯曲试验以及动态力学分析（DMA）进行评估。使用方差分析（ANOVA）方法对数据进行统计分析。扫描电子显微镜（SEM）分析表明，随着复合材料中纤维体积的增加，断裂机制从纯粹的脆性断裂转变为延性 - 脆性组合。复合材料的拉伸试验表明，强度和弹性模量随纤维体积增加呈上升趋势。弯曲试验结果也显示复合材料的强度和弹性模量有类似趋势。DMA试验结果表明，含有30%体积分数乌比姆纤维的复合材料表现出高玻璃化转变温度和低损耗角正切值，表明该复合材料比其他复合材料具有更高的刚度。总体而言，结果表明，与其他测试的纤维含量相比，在复合材料中加入30%体积分数的乌比姆纤维显著改善了其力学性能。此外，它们的功能特性，如制造过程简单、成本低和优异的强度重量比，使这些复合材料特别适用于汽车工业、建筑板材和包装等领域的应用。这些因素有助于开发一种高效、可持续、可回收和环保的复合材料。
