Thermal transport in amorphous and semi-crystalline epoxy networks via bond engineering

Thermal transport coefficient (k) is an important property of condensed systems, where establishing microscopic understanding is extremely important for their possible uses under extreme environmental and practical conditions. Here polymers are an important class because they provide different pathways for energy transfer. For example, the heat flow between

two covalently bonded monomers is over 100 times faster than between two non-bonded monomers. Therefore, a delicate balance between these two contributions often provides a guiding tool for the design of tailor made polymeric materials with extraordinary thermal properties. Traditionally most studies have investigated k in the linear polymeric materials, the recent interests have also been directed towards the amorphous and semi-crystalline epoxy networks. Using molecular dynamics simulations, we investigate the factors effecting k of epoxy networks. We emphasize on the importance of the bond types and their influence on the microstructures of amorphous [1] and semi-crystalline [2] networks, with a goal to provide a guiding principle for the tunability in k. While these results are compared with the existing experiments, we also make predictions.

[1] Mukherji and Singh, Physical Review Materials 5, 025602 (2021).

[2] Maurya, Wu, Singh, and Mukherji, ACS Macro Letters 11, 925 (2022).