Using coarse-grained molecular-dynamics simulations, a generic
styrene-(block)-butadiene-(block)-styrene (SBS) triblock copolymer under
lamellar conformation is used in order to investigate the mutual entanglement
evolution when a structure of alternating glassy (S)/rubbery (B) layers is
submitted to an imposed deformation. By varying the amount of loop chains
between each phase, i.e. noncrossing chains, it is possible to generate
different types of S/B interface definitions. A specific boundary driven
tensile strain protocol has been developed in order to mimic "real" experiments
and measure the stress-strain curve. The same protocol is also applied to a
reference state consisting in a directed glassy homopolymers, as well as to an
isotropic glassy polymer. The evolution of initial mutual entanglements from
the undeformed samples during the whole deformation process is monitored. It is
shown for all considered systems that initial entanglements mostly participate
to the preyield regime of the stress-strain curve and that this network is
debonded during the strain-hardening regime. For triblocks with a non-null
amount of crossing chains, the lower the amount is, the longer the memory
effect of the initial entanglement network in the postyield regime is. On the
fly distributions of entanglements, which depart from the postyield regime,
depict memory effects and long time correlations during the strain-hardening
regime. For triblocks, loop chains reinforce these effects.Comment: 10 pages, 11 figure
