A theory for the thermal conductivity of highly viscous chain-like polymer melts

Polymers play a key role in many modern electronic applications. Conventional pure (unfilled) polymers, with inherently low thermal conductivity (<1 Wm−1 K−1), struggle to dissipate accumulated heat, leading to high operating temperatures and an increased risk of premature failure of electronic equipment. To ensure long-term stability and reliability in high-performance electronic systems, a fundamental understanding of how the processes of thermal conductivity connected with underlying polymer dynamics is essential. Here, a microscopic theory of thermal conductivity of pure (unfilled) polymer materials above the melting point is developed. It is demonstrated theoretically that highly viscous linear polymer melts (MW>6×106Da) of polyethylene, polyethylene oxide, and polybutadiene may exhibit giant thermal conductivity values (∼107–109 Wm−1 K−1).