Thermal conductivity of PP/Al(OH)_3/Mg(OH)_2 composites

摘要

Polypropylene (PP) composites filled with aluminum hydroxide (Al(OH)_3) and magnesium hydroxide (Mg(OH)_2) were prepared using a twin-screw extruder. The effective thermal conductivity (k_(eff)) of the composites was measured by means of a thermal conductivity instrument under different testing temperatures. The results showed that the values of k_(eff) increased quickly with an increase the volume fraction (φ_f) of Al(OH)_3/Mg(OH)_2 powder when φ_f was less than 7.1%, then k_(eff) increased slightly as φ_f was varying from 7.1% to 13.3%, while the values of k_(eff) increased obviously when φ_f was more than 13.3%. Under the same conditions, the values of k_(eff) increased nonlinearly with increasing the diameter (d) of the Al(OH)_3/Mg(OH)_2 powder. The values of k_(eff) of the composites increased somewhat with a rise of test temperature. On the basis of the experimental results, the thermal conduction mechanisms of the composite were analyzed and discussed.