Applying agari theory to raising thermal conductivity of Si₃N₄ reinforced LLDPE composites

Aim: We contracted to raise thermal conductivity of Si₃N₄ reinforced LLDPE (linear low-density polyethylene) composites and applied the Agari theory [3] to achieving it. In the full paper, we explain in some detail our experimental research and discuss the experimental results; in this abstract, we just add some pertinent remarks to listing the two topics of explanation and discussion. The first topic is: Experimental work. In this topic we prepare the LLDPE composites with the powder-mixing method. The second topic is: Results and their discussion. Its three subtopics are: The effect of filler content on the thermal conductivity of LLDPE composites (subtopic 2.1), the effect of particle size of the LLDPE on its thermal conductivity (subtopic 2.2) and the thermal conductivity of Si₃N₄/Al₂O₃/LLDPE composites (subtopic 2.3). In subtopic 2.1, we point out that the thermal conductivity of LLDPE composites increases with increasing filler content and reaches 1.42 W/m·K when the filler content is 30 wt.%, nearly seven times that of the LLDPE without filler. In subtopic 2.2, we use Fig. 3 in the full paper to show that the LLDPE composites of large particle size have higher thermal conductivity than those of small particle size. This is because LLDPE composites of large particle size can help filler particles to form effective thermal conductive networks of Si₃N₄ particles. In subtopic 2.3, we find that, as Fig. 4 shows, the joint use of Si₃N₄ particle filler and Al₂O₃ short-fiber filler results in a higher thermal conductivity than using Si₃N₄ filler alone owing to the synergetic effects of two fillers.