Exploration of a Living Anionic Polymerization Mechanism into Polymerization-Induced Self-Assembly and Site-Specific Stabilization of the Formed Nano-Objects

The polymerization-induced self-assembly (PISA) has been developed with great success and rapidly promoted the application of the self-assembly technique in practice. The living anionic polymerization (LAP) is represented as a paragon in polymer chemistry because of its versatility in the synthesis of well-defined model polymers with many advantages. However, the combination of the LAP mechanism with the PISA process is still rarely succeeded and remains a challenge. In this contribution, the LAP PISA was realized by using diblock copolymer polyisoprene-b-polystyrene (PI-b-PS) as a research model. The comprehensive variation of the factors, such as the molecular weights (MWs) of PI and PS segments, targeted MW ratio M_n,PS/M_n,PI, weight solid content, and kinds of comonomers, provided an efficient way to modulate the morphologies. The generated nano-objects included the spherical, wormlike, vesicular micelles, as well as their mixtures. Uniquely, based on the in-situ, site-specific cross-linking of the living species in the final polymerization stage of the LAP PISA process, the generated nano-objects can selectively and efficiently be stabilized by a divinylbenzene agent.