Thermally Conductive Shape-Stabilized Phase Change Materials Enabled by Paraffin Wax and Nanoporous Structural...

Area of Science:

• Materials Science
• Aerospace Engineering

Background:

• Paraffin wax (PW) is a potential material for spacecraft thermal management.
• Low thermal conductivity and leakage issues limit its application in advanced spacecraft thermal control systems.
• Existing thermal conductivity enhancers like expanded graphite (EG) face challenges in achieving high conductivity at low filler content and preventing leakage.

Purpose of the Study:

• To develop thermally conductive shape-stabilized paraffin wax/expanded graphite (PW/EG) composites.
• To enhance the thermal conductivity and stability of phase-change materials for spacecraft thermal management.
• To address the leakage problem associated with paraffin wax-based composites.

Main Methods:

• Two preparation methods were employed: a pressure-induced method and a prefabricated skeleton method.
• Expanded graphite was processed to form a nanoscale porous structure, enhancing capillary action and adsorption.
• The thermal conductivity, latent heat, and cyclic stability of the prepared composites were evaluated.

Main Results:

• The PW/EG composites achieved thermal conductivities of 9.99 W/(m·K) and 10.70 W/(m·K) at 10 wt.% EG loading.
• Latent heats were recorded at 240.06 J/g and 231.67 J/g for the two methods.
• Composites demonstrated excellent stability, with >99% residual mass fraction after 50 thermal cycles and effective reduction of electronic component peak temperatures by at least 23 °C.

Conclusions:

• The developed PW/EG composites offer a novel and cost-effective solution for spacecraft thermal management.
• The nanoscale porous structure of EG effectively mitigates leakage and enhances thermal performance.
• These materials significantly improve the capability of spacecraft thermal control systems.