Hierarchical Self-Assembled Structures from Diblock Copolymer Mixtures by Competitive Hydrogen Bonding Strength

Abstract

In this work we prepared poly(styrene⁻<i>b</i>⁻vinylphenol) (PS-<i>b</i>-PVPh) by sequential anionic living polymerization and poly(ethylene oxide-<i>b</i>-4-vinylpyridine) (PEO-<i>b</i>-P4VP) by reversible addition fragmentation chain transfer polymerization (RAFT) by using poly(ethylene oxide) 4-cyano-4-(phenylcarbonothioylthio)pentanoate (PEO-SC(S)Ph) as a macroinitiator with two hydrogen bonded acceptor groups. When blending with disordered PEO-<i>b</i>-P4VP diblock copolymer, we found the order-order self-assembled structure transition from lamellar structure for pure PS-<i>b</i>-PVPh to cylindrical, worm-like, and finally to PEO crystalline lamellar structures. Taking the advantage of the Δ<i>K</i> effect from competitive hydrogen bonding strengths between PVPh/P4VP and PVPh/PEO domains, it could form the hierarchical self-assembled morphologies such as core⁻shell cylindrical nanostructure.