Stereoregular High-Density Bottlebrush Polymer and Its Organic Nanocrystal Stereocomplex through Triple-Helix Formation

Abstract

We report the synthesis of a well-defined molecular bottlebrush polymer with stereoregular side chains (i.e., syndiotactic PMMA). The simultaneous control over the molecular weight, side-chain tacticity, and architecture allows the macromolecule to stereocomplex with the complementary linear stereoregular polymers (i.e., isotactic PMMAs) in controlled manners. By modulating the feed ratio of the complexing materials and chain length of the linear assembling component, a variety of crystalline materials with different sizes and morphologies, including discrete spherical nanoparticle, multiple-particle assembly, and cross-linked network structure, can be produced. Among these, uniformed sized, stable nanocrystals that exhibit temperature-induced solution assembly and disassembly properties can be derived from a combined process of PMMA triple-helix stereocomplex formation and polymer architecture-directed intramolecular crystallization. This work has established a new, facile synthetic protocol toward stimuli-responsive organic nanocrystals, which is applicable to the fabrication of a wide variety of functional crystal nanomaterials with practical applications.

Grubbs’ and Schrock’s Catalysts, Ring Opening Metathesis Polymerization and Molecular Brushes—Synthesis, Characterization, Properties and Applications

“…Janus bottlebrush block copolymers have been assembled from pseudo-alternating PS/P t BA and PDMS/P t BA molecular brushes and studied by Johnson and his team [ 118 ]. Qiao and his team have synthesized PMMA molecular brushes with stereoregular (syndiotactic) side chains and an astonishing organic nanocrystal stereocomplex through triple-helix formation was assembled [ 161 ]. PMMA-Fullerene peapod nanoparticles have also been assembled by the same team [ 162 ].…”

Synthesis of Isotactic-block-Syndiotactic Poly(methyl Methacrylate) via Stereospecific Living Anionic Polymerizations in Combination with Metal-Halogen Exchange, Halogenation, and Click Reactions

“…The unique structures and properties of synthetic polymers have attracted attention from both fundamental and application viewpoints [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Furthermore, these stereoregular polymer chains have been incorporated into various well-defined polymers, such as block, star, graft, and end-functionalized polymers, to create novel properties and functions [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ].…”

Microgels based on isotactic poly(styrene): Synthesis and characterization

“…Even with this limited influence polymer structures with a vast range of application potential have been synthesized over the last years. The stereoregularity of those polymers often leads to crystallinity and can be used to induce for example complexation of complementary polymers . In contrast to radical polymerization methods, coordinate polymerization offers control of tacticity but is usually incompatible with aqueous emulsions.…”