One‐pot synthesis of hyperbranched glycopolymers by RAFT polymerization

Abstract

Soluble hyperbranched glycopolymers were prepared by copolymerization of glycan monomers with reversible addition-fragmentation chain transfer polymerization (RAFT) inimers in a simple one-pot reaction. Two novel RAFT inimers, 2-(methacryloyloxy)ethyl 4-cyano-4-(phenylcarbonothioylthio) pentanoate (MAE-CPP) and 2-(3-(benzylthiocarbonothioylthio) propanoyloxy)ethyl acrylate (BCP-EA) were synthesized and used to prepare hyperbranched glycopolymers. Two types of galactose-based saccharide monomers,, containing a methacrylate and an acrylamide group, respectively, were also synthesized and polymerized under the mediation of the MAE-CPP and BCP-EA inimers, respectively. In addition, hyperbranched poly (proGal-M), linear poly(proGal-A), and hyperbranched poly(pro-Gal-A) were generated and their polymerization kinetics were studied and compared. An unexpected difference was observed in the kinetics between the two monomers during polymerization: the relationship between polymerization rate and concentration of inimer was totally opposite in the two monomer-inimer systems. Branching analysis was conducted by using degree of branching (DB) as the measurement parameter. As expected, a higher DB occurred with increased inimer content. Furthermore, these polymers were readily deprotected by hydrolysis in trifluoroacetic acid solution resulting in watersoluble polymers. The resulting branched glycopolymers have potential as biomimetics of polysaccharides.

Fucoidan-Mimetic Glycopolymers as Tools for Studying Molecular and Cellular Responses in Human Blood Platelets

“…A similar trend was observed regarding the polydispersity ( Ð = 1.23, 1.42, and 1.79 for glycopolymers 4 , 5 , and 6 , respectively) which also increased with increasing [M]:[CTA] ratio (Table ). RAFT polymerization commonly yields polymers with narrow dispersity ( Ð < 1.2), but previous studies have shown that long reaction time (≥24 h) and increasing [M]:[CTA] ratio gives broader dispersity . In comparison, all RAFT‐derived glycopolymers showed significantly lower M n than glycopolymer 2 ( M n = 90 600 g mol −1 ) which was synthesized by thiol‐mediated chain transfer free‐radical polymerization (Table ).…”

“…RAFT polymerization commonly yields polymers with narrow dispersity (Ð < 1.2), but previous studies have shown that long reaction time (≥24 h) and increasing [M]:[CTA] ratio gives broader dispersity. [20][21][22] In comparison, all RAFT-derived glycopolymers showed significantly lower M n than glycopolymer 2 (M n = 90 600 g mol −1 ) which was synthesized by thiol-mediated chain transfer free-radical polymerization ( Table 1).…”

Modification of polysulfone hollow fiber ultrafiltration membranes using hyperbranched polyesters with different molecular weights

“…In the earlier literature, many synthetic techniques have been reported to prepare HBPs, such as polycondensation of AB x monomers, self‐condensing vinyl polymerization (SCVP), self‐condensing ring‐opening polymerization (SCROP), proton‐transfer polymerization (PTP), and so on. Wei prepared the soluble hyperbranched glycopolymers by the copolymerization of the glycan monomers with reversible addition–fragmentation chain transfer polymerization (RAFT) inimers in a simple one‐pot reaction. Jena prepared the hyperbranched polyesters (HBPEs) by the melt polycondensation of the 2,2‐bis(methylol)propionic acid (bis‐MPA); the bis‐MPA was used as the AB 2 monomer which contains one carboxyl (A = COOH) and two hydroxyl (B = OH) functional groups, and this is a representative example of the complexity of the structure‐to‐property relationship for HBPs.…”

Synthesis of Glycopolymer Architectures by Reversible-Deactivation Radical Polymerization

“…Wei et al [160] described the synthesis of hyperbranched glycopolymers carrying galactose residues using RAFT inimers (Entry 141-144, Table 3). Galactose methacrylate M20 and galactose acrylamide M102 were polymerized in the presence of R27 and R28, respectively (I4, ethyl acetate, 70 C), to afford fairly uniform hyperbranched glycopolymers (Ð < 1.5) with M n = 1700-29,000 Da.…”