Effect of moisture absorption on the mechanical behavior of banana-bamboo-glass fiber reinforced hybrid composites in NaCl solution

Abstract

Moisture absorption is a major challenge for natural fiber-reinforced composites, often leading to reduced mechanical strength and limited durability in humid environments. This study examines the impact of water exposure on the mechanical and moisture absorption behavior of banana (Ba)–bamboo (B)–glass fiber (G) hybrid composites. The G-B-B-B-G composite exhibited significant moisture sensitivity despite superior mechanical properties, with 3.83 % thickness swelling, resulting in a 12.06 % reduction in tensile strength and a 35.51 % drop in flexural strength after moisture exposure. In comparison, the G-B-Ba-B-G composite demonstrated higher moisture resistance, with only 2.13 % swelling and retention of 90.97 % tensile and 67.32 % flexural strength. Following the immersion, SEM analysis revealed that fiber swelling and void formation were the primary causes of mechanical degradation in the G-B-B-B-G composite, while the incorporation of banana fiber in G-B-Ba-B-G mitigated these effects. These findings highlight the critical role of fiber composition, sequencing, and orientation in enhancing moisture resistance, underscoring their suitability for marine, automotive, and construction applications.