A metal-based microencapsulated phase change material (MEPCM) with high thermal conductivity, electrical insulation and flame retardancy and its application in epoxy resin

Using the “double-layer coating, sacrificial inner layer” method, MEPCM with a thermal expansion void was prepared by encapsulating Sn particles into a magnesium hydroxide shell. The results showed that MEPCM exhibited better thermal reliability than those without a thermal expansion void. More importantly, the Sn was selected as the core material that MEPCM was enabled to have large volume latent heat (425.2 J/cm3) and high thermal conductivity (10.06 W/m·K), and magnesium hydroxide was chosen as the shell material that MEPCM was given great heat absorption ability (260 J/g), excellent electrical insulation performance and flame retardancy. By adding 20 vol% MEPCM to EP, the thermal conductivity of the composite improved 164.9%. The volume resistivity of EP/MEPCM was 2.1×1012 Ω·cm. The pHRR and THR of EP/MEPCM composite were only 471.64 kW/m2 and 12.95 m2, respectively. The existence of MEPCM enhanced the thermal conductivity, electrical insulation performance and flame retardancy of EP.