MedeA® Application Notes for Polymers

The effect of resin molecular architecture on the small strain elastic constants of diamine-cured epoxy thermosets has been studied using classical all-atom simulations conducted within the MedeA®simulation environment. Batches of thermoset systems have been created using chemically similar di, tri and tetrafunctional resins, followed by calculation of stiffness and compliance matrices for each individual model. Analysis of the batches of topologically and geometrically distinct structures using the Hill-Walpole approach yields upper and lower bounds estimates of the moduli differing by typically 1%, enabling critical comparison with experimentally-measured values.

Effect of Resin Molecular Architecture on Epoxy Thermoset Mechanical Properties

The formation of micelles by surfactants was followed by molecular dynamics calculations performed with MedeA-LAMMPS and using the PCFF+ forcefield. An initial model with a random distribution of C9TAC surfactant molecules was built using the MedeA®building capabilities, such as the Molecular Builder and the Amorphous Materials Builder. Results are in agreement with previous simulation studies and available experimental data.

This application note describes the calculation of densities, cohesive energy densities (CED), and enthalpies of vaporization for a range of straight chain hydrocarbon fluids. The construction, simulation, and analysis methodologies employed are reviewed; and the accuracy of atomistic simulation for organic materials and polymers illustrated. Mean absolute errors are 0.23% and 0.28% for densities and heats of vaporization respectively for the PCFF+ forcefield.

Organic Materials Properties: Densities,  Cohesive Energies, and Heats of Vaporization