氧化石墨烯改性苎麻及聚丙烯复合材料的制备与力学性能

Preparation and Mechanical Properties of Polypropylene Composites Reinforced by RF Modified with GO

摘要: 为了提高苎麻纤维(RF)与基体材料的相容性，本文采用碱预处理和氧化石墨烯(GO)表面改性相结合的方法处理苎麻纤维。改性苎麻与聚丙烯(PP)经双螺杆挤出机挤出、注塑成型制成复合材料，过程中加入适量的相容剂马来酸酐(MAH)。对复合材料进行冲击、拉伸、硬度、维卡软化点等测试，对比研究了不同碱处理时间、GO浓度及成份配比对复合材料性能的影响。结果表明，适量GO改性可显著改善纤维与PP基体的界面结合力，促进纤维均匀分散，材料的相关性能均得到了一定程度的改善。如加入经碱预处理3 h及3.0 mg/mL GO浓度改性方法下得到的苎麻5%时，相较纯PP材料，复合材料冲击强度从7.8 kJ/m²提升至35.3 kJ/m²，拉伸强度从15.8 MPa提升至37.9 MPa，硬度增加57%，维卡软化温度提高了16%。

Abstract: To enhance the compatibility between ramie fibers and the matrix material, this study combined alkali pretreatment with graphene oxide (GO) surface modification to treat ramie fibers. The modified ramie fibers were then compounded with polypropylene (PP) via twin-screw extrusion and injection molding, with an appropriate amount of maleic anhydride (MAH) added as a compatibilizer. The resulting composites were subjected to impact, tensile, hardness, and Vicat softening point tests, and the effects of different alkali treatment times, GO concentrations, and component ratios on the composite properties were comparatively investigated. The results indicate that an appropriate GO modification can significantly improve the interfacial adhesion between the fibers and the PP matrix, promote uniform fiber dispersion, and lead to notable improvements in the relevant properties. For example, when 5% ramie fibers pretreated with alkali for 3 h and modified with 3.0 mg/mL GO were incorporated, compared with pure PP, the impact strength of the composite increased from 7.8 kJ/m² to 35.3 kJ/m², the tensile strength from 15.8 MPa to 37.9 MPa, the hardness increased by 57%, and the Vicat softening temperature increased by 16%.