TC in Polymer Formulations

Key Factors that Affect Thermal Conductivity 

The most common approach to improve polymer thermal conductivity is to add thermally conducting fillers.  For applications where electrical insulation is required, electrically insulating fillers such as ceramics are the most common additives.  Many factors can contribute to the thermal conductivity of a filled polymer. 

• At the resin level, polymer matrix crystallinity and backbone architecture may affect thermal conductivity though this effect is small in our materials. 
• The intrinsic thermal conductivity of the additive is a primary driver of formulation TC but not the only factor.
• Good dispersion of the filler improves the likelihood of percolation
• Orientation of anisotropic filler relative to direction of heat flow
• Thermal resistance at polymer/filler interface 
  • Thermal resistance from mismatch in density of state / phononic vibrational modes in polymer and filler
  • Poor polymer adhesion to filler may increase thermal resistance
  • Good adhesion may prevent percolation of thermally conducting fillers