高导热有机硅胶粘剂的制备与性能研究

Study on preparation and performance of high thermal conductivity organic silicone adhesive

利用大粒径、小粒径的球形氧化铝以及小粒径的角形氧化铝按质量比6∶3∶1进行复配,然后用硅烷偶联剂[n(CG9)∶n(CG10)=1∶1]改性氧化铝复配粉,填充量为85%。研究随着改性剂质量比(0、0.6%、1.2%、1.8%和2.4%)的增加,胶粘剂的吸油值、黏度、热导率、力学性能、电学性能、耐冷热冲击性能和邵氏硬度等性能的变化,并最终确定了综合性能较好的改性剂用量;然后用质量比为0.5%的硅烷偶联剂KH-550改性相同粉体,相同填充量下,两者进行了各性能的对比。研究结果表明:用硅烷偶联剂[n(CG9)∶n(CG10)=1∶1]进行氧化铝复配粉改性的较佳质量比为1.2%,改性后胶粘剂的综合性能比未改性的要好,说明改性后的粉体与基体具有很好的相容性,改性剂分子上的有机基团成功包覆在粉体表面。该改性剂改性的胶粘剂比KH-550改性的胶粘剂热导率要高,力学性能以及电学性能优异。

The spherical alumina with large particle size,small particle size and angular alumina with small particle size were compounded according to the mass ratio of 6∶3∶1,and then the silane coupling agent [n(CG9)∶n(CG10)=1∶1] was used to modify the alumina compound powder,and the filling amount was 85%. The oil absorption value,viscosity,thermal conductivity,mechanical properties,electrical properties,cold and hot shock resistance and Shore hardness of the adhesive were studied with the increase of modifier mass ratio(0,0.6%,1.2%,1.8%,and 2.4%),and the amount of modifier with good comprehensive performance was determined. Then the same powder was modified by KH-550 with the mass ratio of 0.5%,under the same filling amount,the properties of two powders were compared. The research results showed that the best mass ratio of alumina compound powder modified by silane coupling agent [n(CG9)∶n(CG10)=1∶1] was 1.2%. The comprehensive performance of the modified adhesive was better than that of the unmodified,indicating that the modified powder had good compatibility with the matrix,and the organic groups on the modifier molecules were successfully coated on the surface of the powder. The adhesive modified by this modifier had higher thermal conductivity,excellent mechanical and electrical properties than the adhesive modified by KH-550.