(544h) Predicting Structure and Vitrification in Toughened Epoxy Thermosets with Million-Particle Molecular Dynamics | AIChE

(544h) Predicting Structure and Vitrification in Toughened Epoxy Thermosets with Million-Particle Molecular Dynamics

Authors 

Jankowski, E. - Presenter, Boise State University
The cross-linked network of epoxy thermosets and the nanostructure of embedded thermoplastics determine the cured material's mechanical properties. Because the bonding network and toughener phase-separation depend on the temperature history experienced during curing, it is useful to know how sensitive nanostructure and material properties are to the cure temperature history. In this work we present molecular dynamics investigations into reacting epoxy morphologies using the epoxpy package developed for HOOMD-Blue. We show how coarse-grained models of reacting epoxy thermosets simultaneously permit access to million-particle volumes and empirically validated curing dynamics, enabling the identification of models that balance computational cost with the ability to compare against experiments. We demonstrate how modulation of the curing temperature can be used to control the cured microstructure and mechanical properties. We also demonstrate the accuracy of gelation and glass transition predictions with the coarse model over a wide range of degrees-of-curing. We conclude with a discussion of how such tools can be used to predict residual stresses and inform the processing strategies used to fabricate carbon-fiber composites.