Publications

Macromolecules

Budzien, Joanne L.; Lo, Chi S.; Thompson, Aidan P.

Abstract not provided.

Lo, Chi S.; Thompson, Aidan P.; Grest, Gary S.

Using molecular dynamics simulations, a constitutive model for the chemical aging of polymer networks was developed. This model incorporates the effects on the stress from the chemical crosslinks and the physical entanglements. The independent network hypothesis has been modified to account for the stress transfer between networks due to crosslinking and scission in strained states. This model was implemented in the finite element code Adagio and validated through comparison with experiment. Stress relaxation data was used to deduce crosslinking history and the resulting history was used to predict permanent set. The permanent set predictions agree quantitatively with experiment.

Budzien, Joanne L.; Lo, Chi S.; Grest, Gary S.; Thompson, Aidan P.

Abstract not provided.

Lo, Chi S.; Thompson, Aidan P.

Abstract not provided.

Budzien, Joanne L.; Lo, Chi S.; Curro, John G.; Thompson, Aidan P.; Grest, Gary S.

Constitutive models for chemically reacting networks are formulated based on a generalization of the independent network hypothesis. These models account for the coupling between chemical reaction and strain histories, and have been tested by comparison with microscopic molecular dynamics simulations. An essential feature of these models is the introduction of stress transfer functions that describe the interdependence between crosslinks formed and broken at various strains. Efforts are underway to implement these constitutive models into the finite element code Adagio. Preliminary results are shown that illustrate the effects of changing crosslinking and scission rates and history.