加成型导热电子灌封硅橡胶的研究

Research of Additional Cure Encapsulated Silicone Rubber with Thermal Conductivity

以α,ω-二乙烯基聚二甲基硅氧烷为基胶,配合石英粉、氧化铝、含氢硅油、Pt催化剂等,制成加成型导热电子灌封硅橡胶。研究了导热填料及其用量对加成型导热电子灌封硅橡胶性能的影响。结果表明,石英粉与氧化铝填料都可以提高液体硅橡胶的导热性能,但是随着填料的粒径增大,硅橡胶的机械性能逐渐下降;对比两种导热填料,石英粉体系液体硅橡胶的机械性能较好,而氧化铝体系液体硅橡胶的粘度更低;以α,ω-二乙烯基聚二甲基硅氧烷用量为基础,增加氧化铝添加量,发现导热液体硅橡胶的机械性能呈现下降的趋势,而粘度、导热率则呈现增加的趋势。当氧化铝的用量低于220质量份时,粘度增加的趋势低于导热率增加的趋势,而当用量高于220质量份时,粘度增加的趋势高于导热率增加的趋势。所以考虑导热率、粘度等因素,认为氧化铝用量在200～250份时胶料的综合性能较好,此时胶料粘度介于3 000～4 000 mPa.s,而导热率可达到0.8～0.9 W/m.K。

The additional cure encapsulated silicone rubber was made by taking α,ω-divinyl polydimethylsiloxane as basic material,alumina and quartz powder as filler,hydrogen silicone oil and Pt catalyst as agent.The influence of alumina and quartz powder on the properties of additional cure encapsulated silicone rubber was studied.The results showed that the quartz powder and alumina fillers can improve the thermal conductivity of liquid silicone rubber,and when the filler particle size increased,the mechanical properties of silicone rubber decreased.Comparing alumina and quartz powder,quartz powder may provide liquid silicone rubber good mechanical properties,while alumina may provide liquid silicone rubber low viscosity.When increasing alumina,mechanical properties of liquid silicone rubber decreased,while the viscosity and thermal conductivity increased.When the amount of alumina was less than 220 phr,the trend of increasing thermal conductivity was faster than increasing the viscosity,and when the amount was more than 220 phr,the trend of increasing viscosity was faster than increasing thermal conductivity.When the optimal amount of alumina was 200～250 phr,liquid silicone rubber showed good performance,the viscosity was 3 000～4 000 mPa·s,while the thermal conductivity can reach 0.8～0.9 W/m·K.