Topological polymer chemistry by dynamic selection from electrostatic polymer self-assembly

Abstract

A collection of recent developments in topological polymer chemistry is presented. First, topological isomerism occurring on randomly coiled, flexible polymer molecules having cyclic and linear structures is discussed. Second, an electrostatic self-assembly and covalent fixation strategy has been developed for the synthesis of polymeric topological isomers. These isomers have double cyclic, manacle-, and theta-shaped constructions, and are prepared by using either linear or star telechelic polymer precursors having moderately strained cyclic ammonium salt groups, which carry multifunctional carboxylate counteranions. A technique of reversed-phase chromatography (RPC) is demonstrated as an effective means to separate polymers with different topologies, especially polymeric topological isomers. A further extension of topological polymer chemistry has been observed by dynamic selection from electrostatic polymer self-assembly to enable the effective formation of tadpole-shaped, cyclic-linear hybrid topologies.

Advanced Developments in Cyclic Polymers: Synthesis, Applications, and Perspectives

“…In this method, electrostatic assembly occurs oriented by interaction between aquaternary ammonium cation and acarboxylic anion to form ac yclic ionic complexw hich further undergoes either substituted or covalent formationr eactions to generate the cyclic polymers as shown in Figure 2. [29,[34][35][36][37][38][39][40][41][42][43][44][45] Cyclic polymers produced from this method also have been functionalized with ÀCCH and ÀN 3 groups,and thus enable constructing topologically different cyclic polymer composites, such as bridged and spiro multicyclic topologies, via click cycloaddition reactions. [29]…”

Self-assembly and chemical processing of block copolymers: a roadmap towards a diverse array of block copolymer nanostructures

“…In dilute solution, the collapsed globules at the ends of the chain may merge together to form a unimolecular macrocycle, with the fused globule forming the pearl, and the B block forming the ring [61]. Architectural polymers have been highlighted in recent reviews by Hadjichristidis [94], Tezuka [291][292][293], Hirao [294], Liu [95] and their coworkers.…”

Synthesis of cyclic polymers and topology effects on their diffusion and thermal properties

“…We have developed a process called electrostatic self-assembly and covalent fixation (ESA-CF), which utilizes a linear or star telechelic prepolymer with cyclic ammonium end groups and a multicarboxylate counterion. [29][30][31][32] The prescribed combination of a telechelics and a counteranion forms a predesigned architecture via electrostatic selfassembly. In this process, a kinetic agglomerate at a high concentration restructures to yield a thermodynamically favored ionic complex with the smallest possible number of components in a dilute solution by keeping the charge balance (Scheme 1).…”