热固性树脂中孔隙形成条件的定量测试方法与影响因素

根据热固性树脂基复合材料的热压成型特点和扩散形成孔隙机制 , 建立了一种离线的孔隙形成条件量测试方法 , 可实现孔隙率2树脂压力变化关系的定量测定。采用该方法研究了两类环氧树脂体系固化过程中胶温度、 相对湿度、 树脂压力等条件对孔隙形态和分布的影响 , 并与修正的 Kardos气泡模型的理论计算结果进了对比分析。结果表明: 所建立的测试方法可以模拟热压工艺条件离线测定水汽形成孔隙情况 , 结果重复性好不同条件下树脂压力与孔隙率的关系均呈指数衰减的变化规律 ; 凝胶温度和相对湿度对孔隙率影响显著; 树脂类明显影响孔隙率大小和形态分布。研究结果为热压工艺复合材料孔隙缺陷的控制提供了重要的测试方法和验依据。

Quantitative measuring method and influencing factors of void formation conditions in thermosetting resins

An off-line measuring method of void formation conditions was designed based on the characteristics of the hot press process for resin matrix composites and the mechanism of void formation cont rolled by diffusion. This method can quantitatively determine the relation between resin pressure and porosity. By means of this method , the effect s of gel temperature , relative moisture and resin pressure on void formation conditions in two epoxy systems were studied , including void content , morphology and distribution. The modified Kardos void model was compared with the experiment s. The result s indicate that the method can be used to simulate the void formation process caused by hygroscopic moisture in the hot press process , and it has good repeatability. The evolution of resin pressure vs porosity follows the exponential decay function. Moreover , the gel temperature and relative moisture have great effect s on porosity , while the resin type influences porosity , morphology and dist ribution of voids remarkably. The study provides an important measuring method and experimental evidence for void defect cont rol in composites during the hot press process.