Baroplastic Behavior in Block Copolymer Blends

The study of block copolymer (BCP) blends, composed of the weakly interacting polystyrene-$b$-poly(n-butyl methacrylate) (PS-$b$-PnBMA) and polystyrene-$b$-poly-(n-hexyl methacrylate) (PS-$b$-PnHMA) presented the various composition-dependent phase behaviors arising from a miscible phase between the PnBMA and PnHMA blocks in the BCP blends. As the blend composition varied from PS-$b$-PnBMA to PS-$b$-PnHMA, a lower disorder-to-order transition (LDOT) to a closed-loop phase transition and to an order-to-disorder transition (ODT) on heating were observed. The hydrostatic pressure effects on the various phase behaviors of the BCP blends were further investigated using small-angle neutron scattering (SANS), depolarized light scattering (DPLS) and transmission electron microscope (TEM).