Investigation into the mechanical characteristics of natural fiber-reinforced polymer composites: Effects of flax and e-glass reinforcement and stacking configuration

Abstract

Glass fibers are commonly used to reinforce polymer composites due to their excellent mechanical properties. However, their production is expensive and environmentally unfriendly. To tackle these concerns, researchers are exploring natural fibers as a substitute reinforcement material for polymer composites. These natural fiber-reinforced polymer composites are lightweight, possess a high strength-to-weight ratio, and are biodegradable, making them attractive for a wide range of applications such as automotive, marine, oil, consumer goods, sporting goods, and biomedical fields. In this study, the hybrid effects of using flax and E-glass as reinforcement in epoxy, as well as the stacking configuration of flax/E-glass, on the mechanical properties of the polymer composites were investigated. Laminates with different fiber loadings were created using hand layup vacuum bagging and then subjected to tensile testing following ASTM standards. Statistical analysis tools such as interval graphs, contour plots, surface plots, probability plot, and Pareto chart were employed to assess the impact of the fiber and other parameters. Regression analysis was conducted to develop an empirical equation with a 95 percent confidence limit for all intervals. The results indicated that the properties of the polymer composites exhibited slight improvement from pure epoxy to flax/epoxy composites, significant improvement with E-Glass/epoxy composites, and slight decrease with hybridization. Nevertheless, the hybrid composite still demonstrated much higher tensile strength compared to the pure and flax/epoxy composites. The stacking configuration with treated flax as the core and E-Glass as the skin layer resulted in a tensile strength of 164.23 MPa, surpassing that of flax/epoxy and pure epoxy composites. In conclusion, for medium load structural applications, flax/E-glass/reinforced epoxy composites are recommended through hybridization. The utilization of natural fibers as reinforcement in polymer composites presents a cost-effective and environmentally friendly alternative to glass fibers, while still providing the necessary mechanical properties for various applications.