posted on 2019-05-30, 00:00authored byChowdhury Ashraf, Aniruddh Vashisth, Charles E. Bakis, Adri C. T. van Duin
Atomic oxygen (AO)
is one of the most abundant species present
in the lower earth orbit and is responsible for the aggressive degradation
of polymers used in spacecraft structures. In this investigation,
we use ReaxFF reactive force field molecular dynamics simulations
to evaluate the disintegration of several different thermosetting
epoxy polymers subjected to hypervelocity AO impact. Our simulations
indicate that epoxy with aromatic curative displays higher resistance
to the AO impact because of its stable benzene functionality. Decreased
cross-linking density and increased simulation temperature both lead
to faster disintegration of the polymer. Our simulation results indicate
that ReaxFF force field simulations can be a useful tool to evaluate
the response of various thermosetting epoxies to AO impact and identify
promising candidate materials for spacecraft applications.