Hyperbranched Polymers by Light‐Induced Self‐Condensing Vinyl Polymerization

Abstract

Hyperbranched polymers (HBPs), a unique class of dendritic macromolecules, have received continuous interest from macromolecular scientists due to their inherent properties such as high level of functional terminal units, high solubility, and low viscosity. Despite enormous efforts devoted to the synthesis of HBPs by traditional methods such as single and double monomer strategies involving step-growth polymerization and self-condensing vinyl polymerization (SCVP) processes, there have been limited attempts to employ light-induced processes. Photochemical methods, however, exhibit distinct advantages not characteristically disclosed by traditional ones, such as spatial and temporal control, low energy, and site-specific activation. This review, after a brief summary of the conventional methods, presents the unique features and the key functionalities of the inimers for photoinduced SCVP and strategies for preparing HBPs.

Near‐Infrared‐Induced Cationic Polymerization Initiated by Using Upconverting Nanoparticles and Titanocene

“…In these applications, polymers were synthesized by various photochemical reactions involving free radical, cationic, anionic, and step‐growth polymerizations as well as copper catalyzed click processes, which provides formation of films with different physical and chemical properties. Recently, light‐induced reactions have also become important methodology for controlled/living radical polymerizations, nanocomposites, and hyperbranched polymers, which were useful materials for drug delivery applications . Although most of the technologically applied photochemical processes are based on free radical polymerization, after the discovery of onium salt photochemistry by Crivello, photoinitiated cationic polymerization has gained interest due to their thermal stability, solubility in most of the cationically polymerizable monomers, insensitivity to oxygen and high quantum efficiency to generate reactive species .…”

Recent advances in development of dendritic polymer‐based nanomedicines for cancer diagnosis

“…Preparations strategies for hyperbranched polymers have been discussed in previous reviews (Aydogan, Ciftci, & Yagci, 2018; L. Chen, Ge, et al, 2019; S. Chen, Xu, & Zhang, 2018; Kavand, Anton, Vandamme, Serra, & Chan‐Seng, 2020). The general preparation strategies for hyperbranched polymers are based on either a single‐monomer or double‐monomer methodology (SMM or DMM) (Figure 3).…”

Hydrophilicity Tunable Hyperbranched Polymers by Visible Light Induced Self‐Condensing Vinyl Polymerization

“…[30] As part of our continuous interest for developing photochemical methods for the preparation of complex macromolecular structures, we have recently applied photoinduced processes for the in situ synthesis of hyperbranched polymers by SCVP. [31] Regarding the intentionally designed inimers possessing both initiator and monomer functionalities, these approaches mostly rely on the hydrogen [32,33] or halide abstraction [34] via photoexcited Type II photoinitiators or manganese decacarbonyl, respectively. Additionally, the remaining functional groups were operated as starting points for post-polymerization reactions to give amphiphilic star-hyperbranched block copolymers with a hydrophobic core and a hydrophilic shell that can be used for drug delivery systems, [35,36] optical imaging, [37] and hydrophobic coatings.…”

“…As part of our continuous interest for developing photochemical methods for the preparation of complex macromolecular structures, we have recently applied photoinduced processes for the in situ synthesis of hyperbranched polymers by SCVP . Regarding the intentionally designed inimers possessing both initiator and monomer functionalities, these approaches mostly rely on the hydrogen or halide abstraction via photoexcited Type II photoinitiators or manganese decacarbonyl, respectively.…”