双组分硅烷改性聚醚导热密封胶的制备及研究

Preparation of Two-Component Silane Modified Polyether Thermal Conductive Sealant

以硅烷改性聚醚为基料,氧化铝和氧化锌为导热填料,制备了具有优异导热性能和密封性能的双组分硅烷改性聚醚密封胶。探讨了相对湿度、交联剂和催化剂用量、老化温度对密封胶性能的影响。结果表明,分别增加交联剂和催化剂的添加量,密封胶硫化后硬度和拉伸强度都有明显的提升。每100份基础聚合物树脂中,交联剂用量达到3份、催化剂用量达到1.5份,制得的双组分硅烷改性聚醚密封胶综合性能良好。在不同温度环境中对硫化后的胶体进行烘烤试验,结果显示,当胶体长期在低于75℃的温度下工作,胶体硬度和剪切强度保持稳定;当温度继续升高至85℃,胶体硬度开始降低,剪切强度明显变弱;温度超过90℃后,胶体的硬度和剪切强度在很短的时间内会明显降低,说明胶体内部发生了反应,主链化学键开始断裂,综合性能变差,不适用于高温环境。

Two-component silane modified polyether sealant was prepared with modified polyether as base material,alumina and zinc oxide as thermal conductive fillers.The effects of the relative humidity,content of crosslinking agent and catalyst,and aging temperature on the properties of sealant were discussed.The results showed that the hardness and tensile strength of the sealant were significantly improved by increasing the amount of crosslinking agent and catalyst respectively.The amount of crosslinking agent and catalyst reached 3 parts and 1.5 parts in 100 parts of the polymer resin,and the prepared two-component silane modified polyether sealant had good comprehensive properties.Bake tests were carried out on the vulcanized sealant at different temperatures.When the sealant worked at a temperature lower than 75℃for a long time,the hardness and shear strength of the sealant remained stable.When the temperature rise to 85℃,the hardness of the sealant began to decrease,and the shear strength became weakened.When the temperature exceeded 90℃,the hardness and shear strength of the sealant would remarkable decrease in a very short time,indicating that there was a reaction inside the sealant,molecular bonds began to break,and the comprehensive properties became worse.