The Influence of Fiber Treatment on the Morphology, Water Absorption Capacity and Mechanical Behavior of Curauá Fibers

ABSTRACT

The use of vegetable fibers in the modern engineering industry represents a worldwide need for sustainable low-cost materials with desirable mechanical characteristics, such as high strength, modulus of elasticity and strain capacity. In order to be used as a reinforcement in composite systems, the Curauá fibers' durability and interface characteristics with the different matrices should be improved. The present work aims to characterize and compare the behavior of curauá filaments both in natural and treated conditions focusing on increasing their durability and bond performance. To minimize the degradation and high water absorption, two types of polymeric coatings were impregnated in the fibers: aluminum oxide and sand. Direct tensile tests were performed and correlated to the morphological observations of the fiber structure by SEM images. The adhesion between matrix and fiber was evaluated by pull-out tests. Volumetric changes due to the wetting and drying of the fibers were also analyzed. The results indicated an improvement of the fiber-matrix bond, fiber tensile strength and stiffness after the surface treatments. Additionally, the coating had a positive effect on the hydrophilic nature of the fiber, decreasing its water absorption capacity.

摘要

在现代工程工业中使用植物纤维代表了全世界对可持续的低成本材料的需求，这些材料具有良好的机械特性，如高强度、弹性模量和应变能力. 为了用作复合材料系统中的增强材料，应该改善Curauá纤维在不同基质中的耐久性和界面特性. 本工作旨在表征和比较Curauá丝在自然和处理条件下的性能，重点是提高其耐用性和粘合性能. 为了最大限度地降低降解和高吸水性，在纤维中浸渍了两种聚合物涂层:氧化铝和沙子. 进行了直接拉伸试验，并通过扫描电镜对纤维结构进行了形貌观察. 通过拉出试验对基体与纤维的结合力进行了评价. 分析了纤维的润湿和干燥引起的体积变化. 结果表明，经表面处理后，纤维基体粘结性能、纤维抗拉强度和刚度均有提高. 此外，涂层对纤维的亲水性有积极的影响，降低了纤维的吸水能力.

KEYWORDS:

• Curauá fibers
• surface treatment
• tensile strength
• microstructure
• water absorption capacity
• fiber pull-out

关键词:

• 纤维
• 表面处理
• 抗拉强度
• 微观结构
• 水吸收能力
• 纤维拉拔力

Acknowledgments

The authors acknowledge the financial support from the Brazilian Agencies CAPES and CNPq.

Additional information

Funding

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.