Synthesis of Well-Defined Amphiphilic Star-Block and Miktoarm Star Copolyethers via t-Bu-P₄-Catalyzed Ring-Opening Polymerization of Glycidyl Ethers

Abstract

A comprehensive set of amphiphilic star-shaped block copolyethers with a fixed molecular weight and composition was synthesized via the t-Bu-P 4 -catalyzed ringopening polymerization (ROP) of 2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether as a hydrophilic monomer and decyl glycidyl ether as a hydrophobic monomer. The threeand four-armed star-block copolyethers, i.e., the (AB) 3 -, (BA) 3 -, (AB) 4 -, and (BA) 4 -type star-block copolyethers, where A and B represent hydrophilic and hydrophobic blocks, respectively, were synthesized by the sequential t-Bu-P 4catalyzed block copolymerization using tri-and tetra-alcohol initiators, respectively, according to the core-first method. The homogeneous growth of each arm was confirmed by cleaving the linkages between the initiator residue and polyether arms. The synthesis of the A 2 B 2 -, AB 2 -, and A 2 B-type miktoarm star copolyethers was achieved by the combination of the t-Bu-P 4 -catalyzed ROP and azido-alkyne click chemistry. The azido-and ethynyl-functionalized precursor polyethers with the predicted molecular weights were separately prepared by the t-Bu-P 4 -catalyzed ROP with the aid of functional initiators as well as a terminator. The intermolecular click reaction of the precursors provided the desired miktoarm star copolyethers. All the obtained star-shaped block copolyethers had a comparable monomer composition (degree of polymerization = 50:50) and total molecular weight (ca. 22 200 g mol −1 ) with a narrow dispersity (<1.05). The hydrodynamic diameter and the cloud point analyses for the aqueous micellar solution of the amphiphilic star-shaped block copolyethers revealed that the self-assembly properties were affected by the block arrangements and branched architectures of the amphiphilic polymers.

Tunable temperature‐ and shear‐responsive hydrogels based on poly(alkyl glycidyl ether)s

“…Living anionic polymerization is an effective method for the ring‐opening polymerization of glycidyl ether derivatives to afford polymers of controlled molecular weight and dispersity. All poly(alkyl glycidyl ether)s in this investigation were synthesized via the initiation from an alcohol using potassium naphthalenide as the base.…”

Nano‐Star‐Shaped Polymers for Drug Delivery Applications

“…The ring opening polymerization technique is usually combined with other processes in order to synthesize star‐shaped polymers, typically, with arms developed by the living polymerization techniques explained earlier . Miktoarm stars can also be made by incorporating mixed arms during the cross‐linking stage .…”

“…The ring opening polymerization technique is usually combined with other processes in order to synthesize star-shaped polymers, typically, with arms developed by the living polymerization techniques explained earlier. [121] Miktoarm stars can also be made by incorporating mixed arms during the cross-linking stage. [122] ROP produces stars that are characterized by ester linkages which are desirable biomedical because of the ease of hydrolysis at physiological conditions (Figure 6).…”

Hyperbranched Macromolecules: From Synthesis to Applications

“…Polymerization is driven by addition of a proper initiator to the corresponding monomer. As an example, anionic ring-opening polymerization of glycidol was used to prepare hyperbranched aliphatic polyether that contained one epoxide and one hydroxy group, representing a latent AB 2 monomer [ 22 ].…”