吸湿对氰酸酯胶膜蜂窝夹层结构胶接性能的影响

Effect of Moisture on Bonding Performance of Cyanate Ester Adhesivebonded Honeycomb Sandwich

采用氰酸酯预浸料、氰酸酯胶膜和Nomex纸蜂窝,利用热固化成型方法制备了氰酸酯胶膜蜂窝夹层结构。分析了Nomex纸蜂窝、氰酸酯预浸料、氰酸酯胶膜的吸湿行为,研究了吸湿对氰酸酯胶膜粘接的夹层结构破坏模式的影响,分析了吸湿在氰酸酯胶膜粘接夹层结构中的作用机理,以此为基础提出了减小或消除吸湿影响的措施。结果表明,氰酸酯胶膜及氰酸酯预浸料的吸湿量可以忽略。Nomex纸蜂窝中的湿气对夹层结构的胶接会产生不利影响,湿气的存在会影响胶粘剂对蜂窝的浸润,并且湿气中的水分还会催化氰酸酯的反应,在粘接固化过程中加速胶粘剂的凝胶和黏度增大。为消除纸蜂窝吸湿对胶接的不利影响,采取措施控制胶接环境和待胶接材料的贮存环境、在胶接前充分干燥待胶接材料等措施,可以达到降低待胶接蜂窝中的湿气含量,进而减小其对夹层结构胶接影响的效果。

The honeycomb sandwich were prepared by thermal curing method using cyanate ester resin prepreg, cyanate ester resin film adhesive and Nomex honeycomb. The moisture absorption behavior of Nomex honeycomb,cyanate ester resin prepreg,cyanate ester resin film adhesive were studied,also the effect of moisture on breakage mode of honeycomb sandwich were researched. And then, the influence mechanism of moisture on bonding process was indicated, then the advice to eliminate the influence of moisture was developed. The results show that the moisture of cyanate ester resin prepreg and film adhesive can be ignored, but the moisture in Nomex honeycomb will engender adverse effect on adhesion of the sandwich structure. The moisture can influence the wettability of adhesive to honeycomb, and catalyze the reaction of cyanate ester resin. Then, the gel time of adhesive could be reduced and the viscosity could be increased. Some measures as controlling the environment of adhesion and material storage, and fully drying the pre-bond composite, and so on, should be taken to reduce the content of moisture in honeycomb, thereby reduce the adverse effect of moisture to adhesion of sandwich structure.