Control of microphase-separated structures by tuning the functional groups and the degree of modification for a single block copolymer

Abstract

To control the self-assembled morphology of block copolymers (BCPs), a series of BCPs were synthesized and post-functionalized via click chemistry. More specifically, polystyrene-b-poly(allyl glycidyl ether)s (PS-b-PAGEs) were synthesized via the anionic polymerization of styrene and subsequent catalyzed ring-opening polymerization of the second PAGE block. Thiol–ene click chemistry was utilized for the post-functionalization of the resulting polymers. To investigate the effects of functional side-chains on the interaction between segments, the Flory–Huggins interaction parameter χ was estimated using the radon phase approximation method. The significant increases and decreases in the effective χ (χ_eff) values obtained suggested that the introduction of functional groups significantly influenced χ_eff. Moreover, the morphologies of the synthesized BCPs were then investigated using X-ray scattering and transmission electron microscopy, and it was found that the morphology was also affected by the introduction of functional groups.