Calculation scheme for the evaluation of polymer thermal conductivity

A calculation scheme for evaluating the thermal conductivities of polymers from the data on their chemical structures and degrees of crystallinity has been developed. The scheme is a version of the Vargaftik equation for organic liquids that is modified for polymers. In the modified equation, the heat capacity of a polymer, its density, and the reduced molecular mass of the repeating unit are involved. The effect of polar groups responsible for dipole-dipole interactions or the formation of hydrogen bonds and the effect of the van der Waals volume of the repeating unit of a polymer or the repeating fragment of the network are analyzed. It has been taken into account that atoms in the polymer backbone and in side chains contribute differently to thermal conductivity. The effects of temperature and the degree of crystallinity on the studied characteristic are considered.