混杂填料填充导热硅橡胶性能研究

以甲基乙烯基硅橡胶为基胶,选用不同粒径氮化硅粒子和碳化硅晶须为填料制备了导热硅橡胶.研究表明:大小粒子以最佳比例进行混合填充时橡胶可获较高热导率,并采用Hasselman模型和等效粒径概念来研究混合粒子体系的热导率;将碳化硅晶须和氮化硅粒子并用,在较低用量下体系呈现较高热导率.此外,随混合填料用量增加橡胶热膨胀系数降低,热稳定性提高.

Properties of Heat Conductive Silicone Rubber Filled with Hybrid Fillers

The heat conductive silicone rubber with vinyl endblocked polymethylsiloxane as basic gum and silicone nitride(Si_3N_4) of different particle sizes and silicon carbide whisker as fillers was prepared.The results showed that the silicone rubber incorporated with a mixture Si_3N_4 at a preferable mass ratio(exhibited) better thermal conductivity compared with the case where filler with a single particle size was used;the Hasselman model and the equivalent particle diameter concept were employed to investigate the thermal conductivity of composites.Furthermore,combined use of Si_3N_4 particles and SiC whisker gived composites with higher thermal conductivity compared with Si_3N_4 particle used alone at lower filler volume fraction.In addition,the thermal stability increased with increasing hybrid fillers content,while coefficient of thermal expansion(CTE) decreased.