Effect of polydispersity on the structure factor of a melt of binary multiblock copolymers with a two-length-scale macromolecular architecture

Abstract

A theoretical study on the effect of polydispersity of two-length-scale binary multiblock copolymers on the shape of the structure factor is presented. A bifurcation diagram is constructed showing the partition of the parameter space into domains differing in the way in which the homogeneous melt loses thermodynamic stability. When the polydispersity of the two-length-scale multiblock copolymers is high enough the phase diagram may contain a surface of double spinodal points separating regions of trivial and nontrivial spinodal branches. The information about the location of these regions is an indispensable prerequisite for the construction of a phase diagram, because the type of temperature-induced phase transition caused by the loss of thermodynamic stability of the homogeneous state depends on the range of values of the block copolymer parameters.