Sequence-Regulated Polymers via Living Radical Polymerization: From Design to Properties and Functions

Abstract

Sequence-regulated polymers have been recently designed and synthesized via ruthenium-catalyzed living radical polymerization for unique physical properties and functions. This chapter summarizes the recent advances on the following topics: 1) gradient copolymers via concurrent tandem catalysis of living radical polymerization and in situ transesterification of methacrylates with alcohols; 2) cyclopolymers comprising in-chain large poly(ethylene glycol) (PEG) rings via cation template-assisted cyclopolymerization of PEG dimethacrylates for cation recognition; 3) single-chain folding of amphiphilic random copolymers into compact unimer micelles in water with intramolecular hydrophobic interaction.

Multimode Self-Folding Polymers via Reversible and Thermoresponsive Self-Assembly of Amphiphilic/Fluorous Random Copolymers

“…Single-chain folding (self-folding) of polymers has attracted attention as a promising approach to create functional polymeric nanomaterials with globular three-dimensional architectures and precision nanocompartments. − Selective self-folding involves the precision design of polymeric precursors generally based on functional and/or amphiphilic random copolymers with well-controlled primary structure. Such random copolymers effectively allow the intramolecular association of the functional pendants (side chains) via physical interactions (e.g., hydrophobic, − hydrogen bonding, − , host–guest, , and coordination) by selecting solvents, adding molecules, and/or giving stimuli (e.g., temperature), while they can also undergo the intramolecular cross-linking of the pendants via covalent bond formation. ,− Particularly interesting, the former self-folding system can provide reversibly folded/unfolded polymers with “dynamic” single-chain nanospaces that directly reflect the precision primary structure of the precursor polymers.…”

Access to Bicyclo[4.2.0]octene Monomers To Explore the Scope of Alternating Ring-Opening Metathesis Polymerization

“…Alternating copolymers are of interest for a multitude of applications ranging from the biological to nanoelectronics and catalysis. − Generally, alternating copolymers have been synthesized by radical polymerization − and metal-mediated routes, including CO 2 /epoxide copolymerizations and catalyst transfer polymerizations of heterocycles . However, the introduction of functionality can be limited by reaction conditions.…”

Single-chain crosslinked star polymers via intramolecular crosslinking of self-folding amphiphilic copolymers in water

“…They can thus provide functional nanospaces based on single polymer chains. 17,18,25,27 Recently, we have synthesized various amphiphilic and functional random copolymers via living radical polymerization to create single-chain folding (self-folding) polymers with hydrophobic and hydrogen-bonding interactions in water. [23][24][25][26][27] Compared with conventional microgel-core star polymers, single-chain folding polymers have several inherent features: 1) the primary structure (e.g., molecular weight, monomer composition and sequence, and terminal structure and number) of single-chain folding polymers is identical to that of random copolymer precursors; 2) folding properties are tunable by monomer composition, monomer species, and degree of polymerization; and 3) folding structure is dynamically and reversibly variable by external stimuli.…”