Improvement of the Mechanical Properties by Surface Modification of ZnCl₂ and Polydopamine in Aramid Fiber Composites

Although aramid fiber has the advantage of excellent chemical and mechanical properties, the performance of the composites may be reduced due to the low interfacial adhesion between the fabric and the matrix. The surface of the aramid fiber was modified to improve the interfacial properties. The surface of the aramid fibers was treated with ZnCl₂ and polydopamine. After the pretreated fabrics were made into a composite material by the vacuum-assisted resin transfer molding (VARTM) process, their mechanical performance was investigated. The highest impact energy was shown in the concentration of 6 wt% ZnCl₂ and 1.5 g/L polydopamine, which is 20% better than that of the untreated material. In the bending strength, the condition of 1.5 g/L polydopamine resulted in the highest value and increased by 13% compared to the untreated material. The hybrid surface treatment of ZnCl₂ and polydopamine did not significantly affect the tensile strength.