热处理工艺对玻纤增强聚酰胺66抗老化性能的影响

Effect of Hygrothermal Treatment Processes on Mechanical Properties and Microstructure of Hygrothermally Aged Glass Fiber Reinforced Polyamide 66

通过宏观力学性能测试和微观表征方法研究了不同热处理工艺对25%短玻璃纤维(GF)增强聚酰胺66(PA66)固定板抗老化性能的影响。将用不同热的处理工艺25%GF/PA66固定板放入恒温恒湿环境中(25℃,相对湿度70%),进行定期取样测试。结果表明,热处理温度对湿热老化时的吸湿增重率有明显的影响。20℃水煮温度处理比100℃在降低固定板吸水率、强度保持率及硬度保持率方面均具有更好的效果;“靠模”的加入使得吸湿增重率有轻微下降,总体上有利于拉伸强度和弯曲强度的保持率。但“靠模”的加入使得硬度的数值和保持率均有轻微下降。通过扫描电镜观察弯曲断裂面可以证明,4种热处理工艺下,试样在湿热老化后,玻璃纤维与PA66基体保持了良好的界面黏结强度。因此,实验结果证明“靠模”+常温水煮对25%GF/PA66固定板的吸湿增重率、拉伸强度、弯曲强度和硬度具有良好的保持效果,可有效提高GF/PA66注塑制品的抗老化性能,这为玻纤增强PA66材料的抗湿热老化研究提供了借鉴和参考。

The effects of different hygrothermal treatment processes on the hygrothermal aging properties of 25%short glass fiber(GF)-reinforced polyamide 66(PA66)plates were investigated by macroscopic mechanical properties and microscopic characterization methods.The 25%GF/PA66 fixed plates with different hygrothermal treatment processes were put into the same hygrothermal aging environment for periodic sampling and testing,and the analysis results show that the hygrothermal weight gain rate of fixed plates with different hygrothermal treatment processes decreases to different degrees.The mechanical properties results show that the hygrothermal treatment process improves the hygrothermal aging resistance of the fixed plates,and maintains the high tensile and flexural strength,and surface hardness in the hygrothermal aging environment;the temperature change of the hygrothermal treatment process has a greater impact on the decay of mechanical properties.The bending fracture surface was observed by scanning electron microscopy and it is found that after the hygrothermal treatment,the surface of the extracted fibers is covered with a large amount of resin matrix,and the cavities left by the extracted fibers at the fracture are also less,which indicates that the wet heat treatment can maintain good interfacial bond strength between the glass fibers and PA66 matrix of the specimens.