Abstract:

This study developed a thermally conductive and heat⁃resistant polyethylene （PE） pipe through the melt blending and extrusion of PE with graphite. The effect of graphite content on the thermal conductivity was systematically investigated， and the resulting hydrostatic and mechanical properties were evaluated. The results indicated that an optimal loading of 12 phr of 300⁃mesh graphite yielded a composite with a thermal conductivity of 0.73 W/（m·K）， significantly enhancing the base polymer's heat transfer. Crucially， the composite pipe retained excellent pressure resistance， successfully passing standard hydrostatic tests at 20 °C for 1 h and at 95 °C for 22 h， 165 h， and 1000 h. This work confirms that graphite is an effective filler for fabricating PE pipes suitable for low⁃to⁃medium⁃temperature heat transfer applications without compromising mechanical integrity.

Key words: heat conduction tube, PERT II tube, thermal conductivity, graphite, mechanical property