Heterocomplementary H-Bonding RAFT Agents as Tools for the Preparation of Supramolecular Miktoarm Star Copolymers

Abstract

Supramolecular miktoarm stars (AB 2 type) composed of poly (methyl methacrylate)-polystyrene 2 (PMMA-PS 2 ), poly(isoprene)-polystyrene 2 (PI-PS 2 ), and poly(vinyl acetate)-polystyrene 2 (PVAc-PS 2 ) were successfully synthesized by assembling reversible addition−fragmentation chain transfer (RAFT)-polymerized chains bearing hydrogen-bonding heterocomplementary associating units. To this end, thymine and diaminopyridine-functionalized chain transfer agents were designed to efficiently mediate the polymerization of vinyl acetate, methyl methacrylate, isoprene, and styrene. The selective associations of the resulting hydrogen-bonding macromolecular building blocks PVAc/PS, PI/PS, and PMMA/PS were demonstrated by 1 H NMR in CDCl 3 solutions. Miktoarm stars formation in the bulk was also confirmed by transmission electronic microscopy.