Long-subchain Janus-dendritic copolymers from locally confined click reaction and generation-dependent micro-phase separation

Abstract

Long-subchain Janus-dendritic copolymers composed of PSt and PtBA half-dendrons, up to the third generation, were prepared under alternating chemical and local confinement. All the Janus-dendritic copolymers exhibited generation-dependent microphase separation.

Long‐Chain Hyperbranched Polymers: Synthesis, Properties, and Applications

“…improved the click reaction conditions in highly concentrated solution and in a good solvent, and also by choosing poly(methyl methacrylate) instead of previously used polystyrene chains with disubstituted chain ends to generate steric hindrance that affected the azide‐alkyne click reaction so as to inhibit the intra‐chain cyclization of the seesaw macromonomers, and it indeed caused a negligible self‐cyclized by‐product . They also synthesized a kind of long‐chain Janus‐dendritic copolymer from these seesaw‐type macromonomers via alternate chemical and local confinement . Such a seesaw‐type AB 2 macromonomer strategy was also utilized by Frey et al.…”

“…Recently, a kind of long‐chain Janus‐dendritic polymer with polystyrene and poly( tert ‐butyl acrylate) as each half dendron reported by He et al. was observed to present microphase separation in different morphologies of lamellar and hexagonal phases, which was determined by their generations …”

Click chemistry strategies for the accelerated synthesis of functional macromolecules

“…503 Recently, He reported a novel strategy for preparing dendritic copolymers through click chemistry. 508,521 To achieve the exact Janus arrangement, physical confinement is employed (Figure 18). Excess of one seesaw-type macromonomers, either polystyrene (PSt) or poly(tert-butyl acrylate) (PtBA) with one alkynyl and two bromo units at the chain ends (macro AB 2 ), is used alternatively in each generation growth of the core with the corresponding multivalent azide.…”

“…Janus dendrimers consist of two dendrons with different polarity that facilitate solution self‐assembly, which are usually synthesized separately and “clicked” together in the final step 503 . Recently, He reported a novel strategy for preparing dendritic copolymers through click chemistry 508,521 . To achieve the exact Janus arrangement, physical confinement is employed (Figure 18).…”

“…Schematic representation of the preparation of long‐subchain Janus‐dendritic PSt/PtBA copolymers using physical confinement. Reproduced with permission from Reference 508, 2017, Royal Society of Chemistry [Color figure can be viewed at wileyonlinelibrary.com]…”