Energy Renormalization Approach to Coarse-Grained Epoxy Resins*

Cross-linked networks of epoxy resins are ubiquitous materials with a broad range of applications, thanks to the flexibility in their chemical composition that can be fine tuned to obtain the desired properties. The huge parameter space makes it challenging to optimize the material, and modeling efforts can greatly contribute to their development.
In particular, many properties of epoxy resins stem from fundamental features like cross-linking density, dynamical heterogeneity and relaxation phenomena that do not depend on the fine atomistic structure of the system.

We developed a new coarse-grained molecular dynamics model for epoxy resins. Thanks to a novel energy renormalization technique, the model parameters can be tuned to match the dynamics and mechanical properties of atomistic simulations over a wide range of temperatures. The coarse-grained nature of the model allows for increased computational efficiency and focus on fundamental physical properties of the resin.
We show how tuning these properties affects the dynamical and mechanical behavior of the network.
By highlighting the role of relevant features, the results obtained with this model can guide and accelerate the molecular design and optimization of epoxy resins.