Analyzing the Moisture and Chemical Retention Behavior of Flax Fiber–Ceramic Hybrid Composites for Automotive Underbody Shields

In pursuing enhanced bio-composite properties, filler materials play a pivotal role. This study delves into the impact of ceramic additives on the chemical resistance and moisture durability of flax fiber-reinforced polymers. Utilizing the hand lay-up technique, we developed polyester composites reinforced with flax fibers. Silicon carbide (SiC) and aluminum oxide (Al₂O₃) were chosen as filler components. One batch of flax fibers underwent an alkaline treatment to enhance their properties further using a 5% NaOH solution. The resistance of composite samples to acetic acid and sodium hydroxide was then assessed. Additionally, the moisture absorption patterns of all models were investigated. A thorough comparative analysis was conducted among multiple composite batches. The results highlighted that integrating additives significantly bolstered the chemical and moisture resistance of the composites. Notably, the alkali-treated samples exhibited superior moisture and chemical agent resistance compared to their untreated counterparts.