Shock melting of lamellae-forming block copolymers

Abstract

While the propagation of shocks through monoatomic liquids and solids is now well understood, the response of macromolecular systems to shock compression remains far less studied. Here we use molecular dynamics simulations to study the shock compression of diblock copolymers assembled in a lamellae morphology, which may display outstanding ballistic performance. For the first time, we show that the morphologies observed after the passage of the shock resemble those observed at equilibrium, at a temperature dictated by the compression velocity. In copolymers, shock compression leads to a decrease in the lamellae period, favoring the mixing of the polymer blocks, such that strongly segregated initial morphologies evolve into less segregated phases after the passage of the shock, or can even melt into an isotropic phase for strong shocks.