Phase transition and morphology of polydispersed AB A′ triblock copolymers determined by continuous and discrete simulations

The purpose of this study is to consider the effect of polydispersity in triblock copolymer on its order-to-disorder phase transition and morphology, by supplementing continuous description of polymer indices carried out using random phase approximation by a discrete sampling of the polydispersity performed at the mesoscale level. Both methods confirm that the increase in polydispersity involves a greater stability of the ordered state, in agreement with published data on the effect of polydispersity on diblock copolymers. The morphology simulations reveal that longer blocks are phase segregated and shorter blocks are more or less uniformly distributed throughout the polymer. It is proposed that avoiding very short polymer chains will increase the degree of phase segregation, thus improve the mechanical and conductive properties of proton exchange membrane more efficiently. © 2009 American Institute of Physics.