Abstract: In the work, a surface modification was performed toward alumina (Al2O3) powders by silane coupling agent, and then the modified Al2O3 powders were incorporated into polyethylene (PE) as a conductive filler to fabricate heat-resistant polyethylene (RTPE) composites through melt blending. The effect of Al2O3 powders on properties of the composites was investigated extensively. The results indicated that thermal conductivity of the composites increased with an increase of Al2O3 content, and it was improved by a factor of 2 compared with pure PE when 50 wt% of Al2O3 powders with a size of 38 μm was loaded. However, its mechanical properties decreased gradually and its melt fluidity also became worse, resulting in a poor processability. This study also indicated that Y Agari model could well simulated the thermal conductivity of the composites as a function of Al2O3 content, and the theoretical value was most close to the actual one when Al2O3 content exceeded 30 wt%.

Key words: heat-resistant polyethylene, silane coupling agent, alumina, thermal conductivity, mechanical property