沸水对PI/CF复合材料界面作用机理的研究

研究了聚酰亚胺(PI)／碳纤维(CF)复合材料界面在沸水中的稳定性。结果表明，经沸水浸泡后的复合材料层间剪切强度和界面剪切强度均有所提高，且随水煮时间的延长而增大；试样断面观察表明，水没有对复合材料界面产生破坏作用，力学性能的变化与基体／纤维界面粘结的湿热稳定性有直接关系；沸水对界面的作用机理是，在PI／CF复合材料的界面区，树脂的水解使氢键的数量增加，形成了防水层，阻碍了水沿界面的侵入，同时水松驰了界面局部应力。

STUDY ON MECHANISM OF BOILING WATER ACTING ON THE INTERFACE OF PI/CF COMPOSITE

The stability of the interface of polyimide(PI)/carbon fiber(CF) composite in boiling water is studied. The results show that the inter lamination shear strength and interfacial shear strength of composites improve after being dipped in boiling water, and they increase with boiling time going on. The section observation indicates that water has no destructive effect on the interface, and the mechanical properties are dependent on the moisture stability of interfacial adhesion. The mechanism of boiling water on the interface is discussed. The matrix hydrolysis of PI/CF composite interface leads to the number increasing of hydrogen bond, and water barrier is formed. Then water is prevented to break the interface. In addition, the interfacial local stress is relaxed by water.