Tailoring the Architecture of Molecular Bottlebrushes via Click Grafting‐Onto Strategy

Abstract

Molecular bottlebrush (MBB) refer to a synthetic macromolecule, in which a mass of polymeric side chains (SCs) are covalently connected to a macromolecular backbone densely, representing an important type of unimolecular nanomaterial. The chemical composition, size, shape and surface property of MBB could be precisely tailored by varying the backbones and SCs as well as the grafting density (Gdst). Meanwhile, the topological structure of backbones and SCs could also significantly affect the chemical and physical properties of MBBs. For the past few years, by combining the structure features of MBB, the polymers with diverse architectures using MBB as building block have been synthesized, including linear, branched and cyclic MBB etc. These promising architectural features will bring MBBs with diverse architectures and lots of applications in advanced materials. For this reason, we are interested in giving a briefly summary of the recent progress on tailor of well‐defined MBBs with diverse architectures using grafting‐onto strategy combined with controlled polymerization technique.This article is protected by copyright. All rights reserved

Carbon Dioxide-Derived Poly(Propylene Carbonate) Bottlebrush Polymers: Synthesis, Viscoelastic Properties, and Degradation

“…Direct measurements of the backbone, side-chain, and bottlebrush melt chain dimensions, such as through neutron scattering, are encouraged to more accurately probe the scaling behavior especially in the transition region between combs and bottlebrushes. Additional atomic force microscopy experiments are also warranted to visualize the dimensions and entanglement behaviors. ,, …”

“…The high M e and stiffness of bottlebrushes result in unique properties such as decoupling material stiffness from deformability, rapid self-assembly, and elastic and viscoelastic responses. − Tuning bottlebrush polymer structure and rheology has produced materials for applications including drug delivery, lubricants, medical sensing, pressure sensitive adhesives, antifouling coatings, photonic crystals, 3-D printing, and soft elastomers. − …”

Molecular Bottlebrushes as Emerging Nanocarriers: Material Design and Biomedical Application

“…In the “grafting onto” method, both the backbone and side chain are prepared separately, and then though the chemical reaction of the molecular side chain with a reactive group with the functional polymeric backbone, MBBs are obtained . For example, Chen’s group used high-efficiency click reactions to synthesize MBBs with not only high graft density but also different polymeric backbones and side chains, which enriched the structure of the MBBs. − …”

“…Besides, usually the assemblies are formed through hydrophobic interaction in an aqueous environment, and the stability of their long-time circulation in viv o is facing some challenges. The diameter ( D ) of the MBBs depends on the length and graft density of the side chain, and is generally at 5 to 50 nm, while the length ( L ) depends on the polymerization degree of the main backbone, ranging from 20 to 1000 nm. ,,− Therefore, by variation of the polymerization degree of the backbone and the side chain, MBBs with different sizes can be obtained to meet the requirements of different practical application situations. More importantly, compared with other nonchemically bonded polymer assemblies such as micelles and vesicles, the side chains of MBBs are grafted to the backbone by chemical bonding with better structure stability when applied in complex biological environments.…”

“…53 In the "grafting onto" method, both the backbone and side chain are prepared separately, and then though the chemical reaction of the molecular side chain with a reactive group with the functional polymeric backbone, MBBs are obtained. 54 For example, Chen's group used high-efficiency click reactions to synthesize MBBs with not only high graft density but also different polymeric backbones and side chains, which enriched the structure of the MBBs. 55−58 At present, in order to realize the functional diversification of the MBBs, the combination of multiple polymerization methods has attracted wide attention since just using one single polymerization method is hard to synthesize MBBs to fulfill the requirements of real complex application situations.…”