Thermal Conductive Composites Based On High Density Polyethylene

Due to the excellent comprehensive properties, polymer thermally conductivecomposites are studied by many researchers. In this paper, polymer composites based onhigh density polyethylene matrix were studied, and the research includes a few partsbelow:(1) Colloid graphite was modified by aluminum, titanate and stearic acid. Aluminumbenefited to bending properties, and titanate contributed to tensile strength, while stearicacid benefited to notched izod impact strength. According to the result, aluminum wasthe optimal coupling agent and0.5%was the optimal content.(2) Squama graphite, colloid graphite and expanded graphite were the conductivefillers. The tensile strength and bending properties of composites with squama graphitewere enhanced, with lower elongation at break and notched izod impact strength. Theelongation at break and thermal conductivity of composites with expanded graphitewere improved, with lower tensile strength and bending properties. All in all,composites with colloid graphite with15wt%of content were optimal.(3) With the content of one-dimensional carbon fiber increased, the thermalconductivity, tensile strength and bending properties of HDPE/colloid graphite/carbonfiber composites were enhanced, while with lower elongation at break and notched izodimpact strength. With the content of zero-dimensional Al power increased, theelongation at break and thermal conductivity of HDPE/colloid graphite/Al powercomposites were enhanced, while with lower tensile strength and bending properties.The combination of carbon fiber and Al power could enhance the comprehensiveproperties. POE and EVA were chosen as toughening agent. Compared to EVA, POEhad a better performance.(4) With the sheer rate increased, the apparent viscosity decreased and thenon-Newtonian index was blow1, which followed the law of pseudo plastic fluid. Withthe content of graphite increased, the crystallization temperature Tpof compositesincreased at the same conditions and the Δ Eincreased.(6) The pipe made with the composites could meet the standard “pipes of HDPE”.