The effect of fiber stacking orientation on the mechanical and thermal properties of kenaf fiber/ epoxy laminated composites

This study aimed to obtain the mechanical and thermal properties of kenaf fiber reinforced epoxy laminated composites fabricated using a vacuum assisted resin infusion (VARI) method. The alkaline-treated fibers were arranged in the orientation of 0˚/0˚/0˚/0˚ and 0˚/90˚/0˚/90˚. Density measurement, mechanical testings, and thermogravimetric analysis (TGA) were carried out on epoxy and the composites. The results of the mechanical test showed that the tensile, flexural, and compression strengths of the kenaf fiber reinforced epoxy composites with 0˚/0˚/0˚/0˚ fiber orientation were higher than those of the composites with 0˚/90˚/0˚/90˚ fiber orientation, with the values of (96.61 ± 10.18) MPa, (131.01 ± 6.60) MPa, and (71.96 ± 5.50) MPa, respectively. Scanning Electron Microscope (SEM) observations showed that the composites had good fiber-matrix adhesion. The thermal stability of epoxy was enhanced from 557 °C to 571 °C by incorporating kenaf fiber with 0˚/0˚/0˚/0˚ orientation.

本研究旨在获取采用真空辅助树脂灌注法（vacuum assisted resin infusion, VARI）制备的红麻纤维（kenaf fiber）增强环氧树脂层压复合材料的力学与热学性能。实验中，碱处理后的红麻纤维铺层取向设置为0˚/0˚/0˚/0˚与0˚/90˚/0˚/90˚两种。分别对纯环氧树脂及上述复合材料开展密度测试、力学性能测试与热重分析（thermogravimetric analysis, TGA）。力学测试结果表明，铺层取向为0˚/0˚/0˚/0˚的红麻纤维增强环氧树脂复合材料，其拉伸强度、弯曲强度与压缩强度均高于铺层取向为0˚/90˚/0˚/90˚的复合材料，对应强度值分别为(96.61 ± 10.18) MPa、(131.01 ± 6.60) MPa与(71.96 ± 5.50) MPa。扫描电子显微镜（Scanning Electron Microscope, SEM）观察结果显示，该复合材料具备良好的纤维-基体界面结合性能。通过掺入0˚/0˚/0˚/0˚铺层取向的红麻纤维，可将环氧树脂的热稳定温度从557 ℃提升至571 ℃。