碳纤维增强尼龙66复合材料的热性能

Carbon Fiber Reinforced Nylon 66 Thermal Properties of Composite

采用双螺杆挤出机熔融共混的方法制备了碳纤维(CF)增强尼龙66复合材料(PA66/CF),并利用差示扫描量热仪、热重分析仪、熔融指数仪对其热性能进行测试。结果表明,当碳纤维加入后,复合材料的熔点变化较小,但结晶温度明显提高,且不随碳纤维含量的增加而变化,这表明碳纤能够加快结晶速度。通过非等温结晶动力学的研究发现,随着降温速率的提高,结晶速率及结晶度均降低,这是由于,提高降温速度会使复合材料的黏度增大,链段的阻力增大,链段进入晶格时间变长。通过热重分析实验发现,复合材料最大热降解速率所对应温度升高。熔体流动速率实验表明,碳纤维能使复合材料的内摩擦力增大,熔融指数减小。

Carbon fiber(CF)reinforced nylon 66 composite(PA66/CF)was prepared by means of twin screw extruder melt blending,and its thermal properties were studied by differential scanning calorimeter,thermogravimetric analyzer and melt index analyzer.It was found that with the addition of carbon fiber,the melting point of composite material did not change much,but the crystallization temperature increased,which did not change with the increase of carbon fiber content,indicating that the addition of carbon fiber accelerated the crystallization rate.Through the study of non-isothermal crystallization kinetics,it was found that with the increase of cooling rate,both crystallization rate and crystallinity decreased.This was because the increase of cooling rate increased the viscosity of the composite material,the resistance of the chain segment increased,and the time of the chain segment entering the lattice increased.Through thermogravimetric analysis,it was found that the maximum thermal degradation rate of composite was increased.The melt index experiment showed that carbon fiber could make the internal friction of composite material become smaller.