Erosion Resistance of Polyamide 6 Matrix Composites Reinforced with Oxalic Acid and Silane Coupling Agent Modified Coconut Fiber

Natural plant fiber-reinforced composites have rarely been studied for erosion resistance. This paper modifies coconut fiber with oxalic acid and silane coupling agent (KH550), and investigates the effect of modified fiber reinforcement on the sandblasting erosion performance of polyamide 6 (PA6) and 30% glass fiber-reinforced PA6 (30% GF+PA6) matrices. Coconut fibers with 3 wt%, 5 wt%, and 7 wt% contents were compounded with the two matrices to prepare four composites: NL-CS (oxalic acid-modified fiber/PA6), NL-OL (KH550-modified fiber/PA6), ZQ-CS (oxalic acid-modified fiber/30% GF+PA6), and ZQ-OL (KH550-modified fiber/30% GF+PA6). The damage rate, hardness, and performance improvement rate relative to the original matrices were analyzed. Experimental results show that NL-CS with 5 wt% fiber content exhibits optimal performance, reducing damage rate by 20.9% and increasing hardness by 1.95% compared to pure PA6. For ZQ-OL with 7 wt% fiber content, damage rate decreases by 14.25% and hardness increases by 5.18% compared to 30% GF+PA6. This preparation method provides a reference for developing high erosion resistance natural plant fiber composites.