Synthesis and stereocomplexation of PMMA‐based star polymers prepared by a combination of stereospecific anionic polymerization and crosslinking radical polymerization

Abstract

Novel star‐shaped polymers with various stereo‐regular arm polymers are synthesized by a combination of stereospecific living anionic polymerization and transition metal‐catalyzed radical linking polymerization, in which the terminal halogen mediates the transformation of the growing active species from a carbanion into a carbon radical. Using this technique, a series of star polymers with isotactic and syndiotactic poly (methyl methacrylate) arms can be prepared with various stereocomplexation behaviors.

Direct through anionic, cationic, and radical active species: Terminal carbon–halogen bond for “controlled”/living polymerizations of styrene

“…Actually, it has also been attempted to transform the anionic polymerization of styrene into ring‐opening cationic polymerization of tetrahydrofuran (THF) through the stable carbon–halogen bond using molecular bromine since the 1970s by Burgess et al The direct terminal halogenation during the anionic polymerization, however, rarely proceeded in quantitative yields, because the transformation was somehow suffered from Wurtz‐type coupling reaction. Quite recently, we also reported the quantitative halogenation during the stereospecific living anionic polymerization of MMA using CX 4 (X = Cl or Br) as a halogen source to generate stereoregular poly(methyl methacrylate) with a terminal carbon–halogen bond . Therefore, the mechanistic transformation was accomplished from the anionic polymerization into the subsequent transition metal‐catalyzed living radical polymerization.…”

“…Quite recently, we also reported the quantitative halogenation during the stereospecific living anionic polymerization of MMA using CX 4 (X = Cl or Br) as a halogen source to generate stereoregular poly(methyl methacrylate) with a terminal carbon-halogen bond. 44,45 Therefore, the mechanistic transformation was accomplished from the anionic polymerization into the subsequent transition metal-catalyzed living radical polymerization.…”

Epoxy-functionalised 4-vinylguaiacol for the synthesis of bio-based, degradable star polymers via a RAFT/ROCOP strategy

“…Typically, star polymers synthesised using RAFT in an arm-first approach, are formed by cross-linking vinyl-functionalised polymers with multi-vinyl compounds. 6,[18][19][20][21] This creates a core linked by C-C bonds, the controlled degradation of which is challenging. Some of us have recently reported the polymerisation of 4-vinylguaiacol (4VG), derived by decarboxylation of naturally occurring ferulic acid.…”