低温使用聚氨酯改性环氧树脂密封胶的合成及性能

Synthesis and Performances of Polyurethane-Modified Epoxy Resin Sealants Used at Liquid Nitrogen-Temperature

采用聚氨酯改性韧性环氧树脂和二乙烯三胺固化剂制备了一系列室温固化高性能密封胶。测试结果表明,随着固化剂含量和树脂中柔性链含量的增加,密封胶的断裂延伸率都先增后降,压缩永久形变显著降低。在此基础上,最终得到了初始黏度小于1 Pa·s、断裂延伸率可达193%、压缩永久形变<20%、液氮温度时剪切强度高于13 MPa及剥离强度大于10 kN/m,同时拥有优异的耐高低温循环和耐介质性能的密封胶,可用于低温领域及微小部件的粘接和密封。

A series of room-temperature-curing sealants with good performance were labncated using poiyuremanes modified epoxy resin and diethylenetriamine. The sealant performance was affected by the content of curing-agent and flexible chains, and the sealants with the balance properties between high room temperature and high low temperature mechanical properties were obtained. Under the room temperature condition, the initial viscosity of the resulting sealants is less than 1 Pa·s, the highest elongation is around 193 % and permanent compression set is less than 20 %. Under the liquid nitrogen temperature condition, the shear strength of the resulting sealants is above 13 MPa and their peer strength is greater than 10 kN/m. With the excellent high and low temperature cycle resistance and media resistance, these sealants can be applied in micro electronics and cryogenic temperature area.