Effect of volume fraction on the hierarchical structures in A(BC)2B multiblock copolymers: Assisting in the design of high-performance composites

Abstract

We study the effect of volume fraction on the hierarchical structures in the A(BC)₂B multiblock copolymers using the self-consistent field theory to assist in the design of high performance polymer-based composites. The volume fraction of long-tail A block $f_A$ greatly impacts on the large-scale structures. For example, a transition sequence of $C_5\to C_3\to G_5\to L_5\to \overline{C_5}$ at low ${\chi }_{BC}N$ is observed by increasing $f_A$. In addition, the A volume fraction can also affect small-scale structures, where large $f_A$ prefers hierarchical structures with fewer mid-thin layers. Subsequently, we explore the effect of the $f_B/f_C$ ratio on the stability of the hierarchical structure, where a large $f_B/f_C$ ratio leads to the hierarchical structures with less mid-thin layer for the hierarchical lamellae and hierarchical cylinder at large $f_A>0.5$. Interestingly, for the hierarchical cylinder with $f_A<0.5$, a large $f_B$ block results in the hierarchical cylinder with a more mid-thin layer.