Highly efficient synthesis of heteroarm star-shaped polymers using polymer-linking reaction and their characteristic stimuli-responsive behaviors

Abstract

Heteroarm star-shaped polymers containing independent stimuli-responsive moieties were synthesized by a one-pot arm-linking reaction based on base-assisting living cationic polymerization. Mixing two or more kinds of living polymers followed by the linking reaction with a divinyl compound successfully produced a heteroarm star-shaped polymer containing a number of arm chains with a narrow molecular weight distribution (M w /M n ¼ 1.14-1.48) and high yield. For example, four kinds of linear poly(vinyl ether)s containing oxyethylene and alicyclic pendants were linked quantitatively to give a star polymer without any deactivation of the starting polymers. The heteroarm star-shaped polymers exhibited their unique stimuli-responsive behaviors in water or their film surfaces. Furthermore, linear living poly(2-methoxyethyl vinyl ether) and poly(2-phthalimidoethyl vinyl ether) were linked efficiently despite their different reactivities, producing a heteroarm star-shaped polymer with amino-containing and thermosensitive arms. The obtained star polymer exhibited unique aggregation behaviors in response to both pH and temperature in water. This report demonstrates that this one-pot arm-linking reaction is a facile and effective methodology for synthesis of heteroarm star polymers with various combinations of stimuli-responsive arm chains.

Thermoresponsive star-shaped polymer with heteroarm type with methacrylates: preparation by living radical polymerization method and its topological effect

“…47 Recently, microflow systems have been utilized to tune the star-shaped polymer with heteroarms for methacrylate with OEG units and N,N-dimethylaminoethyl acrylate. 48 Aoshima and co-workers systematically synthesized thermoresponsive heteroarm star-shaped polymers, 49,50 including fluorine-containing block copolymers and heteroarm star-shaped polymers with poly(vinyl ether) backbones. However, to the best of our knowledge, there are no examples of thermoresponsive heteroarm star-shaped polymers with methacrylate with OEG chains as the hydrophilic arm and PMMA as the hydrophobic arm, using Ru catalyst.…”

Facile one‐shot synthesis of functional star‐shaped polymers by domino‐type living cationic copolymerization

“…Heteroarm star polymers containing pH‐responsive polyamine arms and thermosensitive arms have been efficiently synthesized in a one‐pot method, which has been demonstrated to assemble in water in response to both pH and temperature . Fluorine‐containing star‐shaped polymers have also been obtained and have been shown to exhibit unique solubility …”