Empirical universal approach to describing the thermal conductivity of amorphous polymers: Effects of pressure, radiation and the Meyer–Neldel rule

Abstract

In this study, we propose and validate a universal temperature-dependent model for characterizing the thermal conductivity of amorphous polymers over a wide temperature range. Our approach captures key features in the thermal conductivity data, including a plateau, an inflection point, and the subsequent increase and saturation with rising temperature. Importantly, this model proves effective not only for pristine amorphous polymers but also for polymers subjected to external influences. We investigate the temperature-dependent thermal conductivity of amorphous polymer materials under various external conditions, such as hydrostatic pressure, radiation exposure, and the incorporation of fillers. Our analysis reveals novel insights into the dual-channel heat transfer mechanisms within amorphous polymers. Specifically, we observe a linear relationship between the logarithm of the “coherence” conductivity pre-factor and the characteristic energy, consistent with the Meyer–Neldel rule governing thermal conductivity. This research advances our understanding of thermal transport in amorphous polymers and underscores the applicability of the proposed universal model in describing complex thermal behavior across different conditions.