RAFT-Based Polymers for Click Reactions.

Elena V Chernikova,Yaroslav V Kudryavtsev

doi:10.3390/polym14030570

Abstract

The parallel development of reversible deactivation radical polymerization and click reaction concepts significantly enriches the toolbox of synthetic polymer chemistry. The synergistic effect of combining these approaches manifests itself in a growth of interest to the design of well-defined functional polymers and their controlled conjugation with biomolecules, drugs, and inorganic surfaces. In this review, we discuss the results obtained with reversible addition–fragmentation chain transfer (RAFT) polymerization and different types of click reactions on low- and high-molar-mass reactants. Our classification of literature sources is based on the typical structure of macromolecules produced by the RAFT technique. The review addresses click reactions, immediate or preceded by a modification of another type, on the leaving and stabilizing groups inherited by a growing macromolecule from the chain transfer agent, as well as on the side groups coming from monomers entering the polymerization process. Architecture and self-assembling properties of the resulting polymers are briefly discussed with regard to their potential functional applications, which include drug delivery, protein recognition, anti-fouling and anti-corrosion coatings, the compatibilization of polymer blends, the modification of fillers to increase their dispersibility in polymer matrices, etc.

Highlights

The non-trivial macromolecular architectures, including various chain topologies, block and graft copolymers, hybrid polymers, etc., have become available due to accelerated progress in the techniques of anionic living polymerization and reversible deactivation polymerization [1,2]
The review addresses click reactions, immediate or preceded by a modification of another type, on the leaving and stabilizing groups inherited by a growing macromolecule from the chain transfer agent, as well as on the side groups coming from monomers entering the polymerization process
We considered only one type of reversible deactivation radical polymerization

Summary

Introduction

The non-trivial macromolecular architectures, including various chain topologies, block and graft copolymers, hybrid polymers, etc., have become available due to accelerated progress in the techniques of anionic living polymerization and reversible deactivation polymerization [1,2]. In combination with photoenol chemistry, a triblock copolymer of poly(isoprene-co-styrene)-b-(poly(ethyl acrylate)-b-(poly(ethylene oxide) was synthesized through the thermally induced hetero Diels–Alder cycloaddition followed by the photo-induced ligation coupling of three different macromolecules into one chain Another methodology for the synthesis of α-functional polymers in a one-pot simultaneous polymerization accompanied by an isocyanate “click” reaction was described in [94]. A similar approach was applied to produce (1) telechelic homo and block copolymers of PMMA, poly(diethylene glycol monomethyl ether methacrylate), poly(ethylene glycol monomethyl ether methacrylate), and poly(lauryl methacrylate) bearing terminal pentafluorophenyl cyanovaleriate groups able to participate in the click reaction with thiols and amines [197]; and (2) hetero telechelic biotin–maleimide PNIPAM able to form streptavidin–bovine serum albumin polymer conjugates [198]. Modification of dithiobenzoate group into alkyne group [199]

R Group Modification Approach

Post-Modification of Side-Group Approach

Findings

Conclusions