Theory of Mesophases of Triblock Comb-Shaped Copolymers: Effects of Dead Zones and Bridging

ABSTRACT: A theory describing the equilibrium morphology and structural properties of solvent-free mesophases of ABA triblock copolymers comprised of comb-shaped blocks is developed using a strong-stretching self-consistent field (SS-SCF) analytical approach with architecture-dependent parameters of the molecular potential. Morphological phase diagrams are constructed by implementing a two-layer model of convex solvent-free brushes which enables us to account for the effect of dead zones on binodals separating regions of thermodynamic stability of spherical, cylindrical, and lamellar mesophases. Fractions of the middle comblike B blocks forming bridges and loops between neighboring A domains are calculated for all of the morphologies as a function of the architectural parameters of the blocks. These analytical calculations are supplemented by numerical Scheutjens-Fleer selfconsistent field (SF-SCF) simulations of convex solvent-free brushes of comblike polymers that mimic the matrix in the ABA triblock copolymer mesophases. The predicted domain sizes and interdomain distances are compared to experimental data.

Automated summary

In this study, a theory describing the equilibrium morphology and structural properties of solvent-free mesophases of ABA triblock copolymers is developed. The effect of dead zones on the stability of different mesophases is considered by implementing a two-layer model. The predicted domain sizes and interdomain distances are compared to experimental data.