Theoretical analysis and development of thermally conductive polymer composites

The effects of phonon scattering and filler connectivity on the heat conduction of polymer composites were investigated using various types of thermally conducive fillers. A theoretical model of thermal conductivity including the concept of phonon scattering in a two-phase material was proposed. Filler interconnectivity was defined from the theoretical model and used to evaluate the filler connectivity in thermally conducive polymer composites (TCPCs). Polymer-filler interfacial phonon scattering rarely influenced the heat conduction of the TCPCs in the absence of interfacial modifications. Filler-filler interfacial phonon scattering was determined to be the main cause of the low thermal conductivity of TCPC even in the presence of filler connections. Filler connectivity was found to be a major factor determining the thermal conductivity of TCPC. Incorporation of fusible metal solders enhanced the filler connectivity, thereby increasing the thermal conductivity. Finally, an advanced and injection-moldable hybrid material for effective heat conduction was developed by increasing the filler connectivity using strategic methods.