Computational Prediction of Mechanical Properties of Glassy Polymer Blends and Thermosets

Abstract

Atomistic simulations of the elastic constants of glassy polystyrene-poly(2,6-dimethyl-1,4- phenylene oxide) blends and 4,4’-diamino-diphenyl sulfone cured epoxy thermosets have been performed in order to examine the precision and accuracy currently achievable using molecular simulations. Bounds estimates obtained using moderately sized batches of independent amorphous structures have been shown to be comparable in magnitude to those obtained in most experiments. For the blend systems, the variation in tensile moduli with composition has been found to be very close to that observed experimentally, and rational explanations for the small ~16% discrepancy in absolute values have been given. In the case of the epoxy-based thermosets, good agreement with experimental moduli suggests that the approach used to create the crosslinked models leads to chemically and physically realistic models of these complex materials