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

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 chi was estimated using the radon phase approximation method. The significant increases and decreases in the effective chi (chi(eff)) values obtained suggested that the introduction of functional groups significantly influenced chi(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.