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

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 Curaua fibers' durability and interface characteristics with the different matrices should be improved. The present work aims to characterize and compare the behavior of curaua 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.

Automated summary

The use of vegetable fibers in modern engineering industry is a global need for sustainable and low-cost materials with desirable mechanical characteristics. This study aims to improve the durability and bond performance of Curaua fibers by applying different polymeric coatings. The results show that the surface treatments have a positive effect on the fiber-matrix bond, fiber tensile strength, and stiffness.