Environmental effects on the durability and the mechanical performance of flax fiber/bio-epoxy composites

Abstract

The growing usage of bio-composite materials in different engineering applications demands a thorough understanding of their performance during their service. Extreme environmental conditions, such as warm, humid, and freezing environments, among others, can degrade the mechanical properties of the bio-composites when they are exposed to harsh environmental conditions. In addition, the use of these composites in underwater applications can also shorten their life cycle. In this work, the durability and mechanical performance (tensile and flexural behavior) of flax/bio-epoxy composites exposed to different environmental conditions were evaluated. These conditions were chosen to replicate those found outdoors that can affect the durability of these materials: water immersion, warm humid environment and freeze-thaw conditions. Moisture and water absorption behavior were evaluated and the water content (or exposure time) was related to the physical changes and mechanical properties. Results show that the mechanical properties of flax/bio-epoxy composites are clearly degraded by water ageing when they are compared to the "as manufactured" composites. The tensile strength and modulus is decreased approximately by 9% and 57%, respectively for water saturated (immersed in water until saturation) samples compared to as manufactured samples. On contrary, this reduction rate is only 0.8% and 3%,

Dynamic Mechanical Behavior Analysis of Flax/Jute Fiber-Reinforced Composites under Salt-Fog Spray Environment

“…Natural fiber-reinforced composites (NFRPs) have received growing attention in the last decades, both from the academic world and from industries, thanks to their specific mechanical properties, reduced cost and advantages for health and recyclability. Nevertheless, this class of innovative materials shows also some drawbacks, such as their limited aging resistance in humid or wet environmental conditions, i.e., an extensive literature shows that NFRP materials experienced dramatic degradation of their quasi-static mechanical properties when exposed to these environments [10][11][12][13][14][15][16][17][18]. This can be partially ascribed to the softening and plasticization phenomena of natural fibers and thermoset matrix [19,20].…”

Influence of hydrothermal ageing on the fatigue behaviour of a unidirectional flax-epoxy laminate

“…In the present study, we investigate the influence of hydrothermal ageing on the fatigue behaviour of a purely unidirectional flax epoxy composite. Indeed, the influence of hydrothermal ageing has been poorly studied whether on the static properties [15][16][17][18][19] or cyclic behaviour [20][21][22].…”

“…Assarar et al [23] observed on a flax/epoxy laminate after 40 days of immersion at room temperature a decrease in tensile strength and modulus of 25% and 39% respectively and an increase in strain at failure of approximately 63%. Moudood et al [18] reported a decrease by 9% and 57% for the tensile strength and modulus, respectively, for a unidirectional flax/bio-epoxy composite after immersion until saturation. Li and Xue [15] studied the influence of water immersion time and temperature on the tensile properties of an unidirectional flax/epoxy composite.…”

Water Absorption and Hygrothermal Aging Behavior of Wood-Polypropylene Composites

“…Bio-sourced materials, the most abundant resources on the planet, are emerging as reinforcing materials for composites, which have attracted much scientific and industrial attention owing to their attractive advantages such as renewability, biodegradability, sustainability, low density, low cost and better mechanical properties [1][2][3][4][5]. At present, the most common reinforcing material is glass fibers, but the manufacturing process of glass fibers and their products is harmful to the human body, such as dermal and respiratory irritation, and even cancer [6][7][8].…”