复合处理碳纤维增强聚酰亚胺复合材料力学性能

Mechanical properties of compound modification carbon fiber reinforced thermoplastic polyimide

采用浓硝酸氧化和聚酰亚胺(PI)包覆复合方法对短切碳纤维(CF)进行表面改性,提高CF增强热塑性聚酰亚胺复合材料(CF/TPI)力学性能。采用比表面积及孔容分析、原子力显微镜、扫描电子显微镜、热重分析仪研究了CF表面处理前后结构和形貌的变化。结果表明:CF经浓HNO3处理后比表面积增加144.2%,CF表面沟壑加深;复合处理后有PI层包覆在CF表面;包覆处理后CF耐热性能提高。力学性能测试表明,经过包覆处理后CF/TPI复合材料的拉伸强度比未处理的提高11.34%,弹性模量提高109.2%,弯曲强度提高18.78%,冲击强度提高74.15%。

To improve the mechanical properties of the short cut carbon fiber reinforced thermoplastic polyimide composites （CF/TPI）, the compound modification method of nitric acid oxidation and polyimide coating was adopted to modify the CF. The treated and untreated CF were characterized by BET, AFM, SEM and TGA. The results show that the specific surface area of CF increases 144.2% after nitric acid oxidation, by increasing the roughness of CF. A PI layer is coated on the CF, and the CF thermal stability increases after coating PI. The tensile strength, elastic modulus, flexural strength and impact strength of the CF/TPI composites are improved by 11.34%, 109.2%, 18. 78% and 74.15% respectively after compound modification of the carbon fiber.