Synthesis of Flower‐Like Polybutadiene

Abstract

Synthesis of complex macromolecular architectures exhibiting no chain ends such as flower‐like polymers is still of interest in the aim of investigating their physicochemical properties. For this purpose, poly(3,4‐dimethyl maleic imidoethyl acrylate)‐block‐polybutadiene‐block‐poly(3,4‐dimethyl maleic imidoethyl acrylate) triblock copolymer is synthesized in a convergent manner using a combination of living polymerization (anionic polymerization), reversible deactivation radical polymerization, and click chemistry. This copolymer is self‐assembled in a selective solvent (heptane/THF mixture) of the polybutadiene block leading to the formation of flower‐like micelles in thermodynamic equilibrium in dilute solution. These resulting transient architectures are fixed by covalently crosslinking the micelles core by inducing [2+2] cyclodimerization of the 3,4‐dimethyl maleic imidoethyl groups borne by the short solvophobic blocks under UV irradiation. Single flowers are isolated from residual non‐crosslinked chains by semipreparative size exclusion chromatography (SEC) and characterized by 1H NMR, SEC, dynamic light scattering (DLS), and transmission electron microscopy (TEM).

Flower‐Like Multicompartment Micelles with Janus‐Core Self‐Assembled from Fluorocarbon‐Terminated Pluronics

“…In other words, these MCMs with Janus‐core could be considered to be self‐assembled from the looped macromolecular chains of fluorocarbon‐terminated Pluronics. Owing to the final state of the micellar corona was made up of the looped PEO blocks, such MCMs with Janus‐core were flower‐like (Scheme d) …”