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

• Published in: Polymer journal Vol. 44; no. 6; pp. 541 - 549
• Main Authors: ODA, Yukari, SHIBATA, Takaho, TSUJIMOTO, Hiroyuki, KANAOKA, Shokyoku, AOSHIMA, Sadahito
• Format: Journal Article
• Language: English
• Published: Avenel, NJ Nature Publishing Group 01.06.2012
• Subjects: A stars; Agglomeration; Applied sciences; Chains (polymeric); Exact sciences and technology; Molecular weight distribution; Organic polymers; Physicochemistry of polymers; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Stars; Synthesis; Thermosensitive; Vinyl ethers; One pot reaction; Isobutyl vinyl ether copolymer; Living polymer; Temperature effect; Cationic polymerization; film; Experimental study; Solution polymerization; Chemical coupling; Star copolymer; poly(vinyl ether)s; Cloud point; Monodispersed polymer; Wettability; Preparation; Vinyl ether copolymer; Surface properties; arm-linking reaction; primary amine; Aqueous solution; stimuli-responsive polymer; Block copolymer; heteroarm star polymer; living cationic polymerization
• ISSN: 0032-3896; 1349-0540
• DOI: 10.1038/pj.2012.23

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 (Mw /Mn =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.