Fundamentals of Thermal Conductivity in the Epoxy Polymer Network

Abstract

In metals, the heat is carried predominantly by electrons. However, it is observed in polymers that the thermal conductivity is driven by lattice vibrations known as phonons. The thermal conductivity through an epoxy polymer is controlled by the state, structure, and orientation of the polymer chain network. Basic understanding of the thermal conductivity of epoxy resins is explained through Debye’s theory and Fourier’s law. The theories of correlation between thermal conductivity and thermal diffusivity, explanation of phonon transport in a 2D epoxy network, and electronic contribution of thermal conductivity in undoped polymers lay foundation to the topic of thermal conductivity in epoxy resins. The heat transfer through the epoxy resin is controlled by incorporating high thermal conductivity fillers to form composites, or, by the intrinsic modification of the epoxy nanostructure for improved crystallinity. The thermal degradation of epoxy polymer is proportionally dependant on the thermal conductivity. This chapter covers the basic theories of thermal conductivity, methods to improve thermal conductivity, factors influencing thermal conductivity, and effect of thermal conductivity in the thermal degradation of epoxy resins.