• Watanabe, Masayoshi
• Kitazawa, Yuzo
• Imaizumi, Satoru
• Ueki, Takeshi
• Tamura, Saki
• Niitsuma, Kazuyuki
• Mcintosh, Lucas D.

Abstract

<p>We investigated a hierarchical morphology change and accompanying sol-gel transition using a doubly thermosensitive ABC-triblock copolymer in an ionic liquid (IL). The triblock copolymer contains two different lower critical solution temperature (LCST) thermosensitive polymers, poly(benzyl methacrylate) (PBnMA) and poly(2-phenylethyl methacrylate) (PPhEtMA), as the end blocks and poly(methyl methacrylate) (PMMA) as the middle block (PBnMA-b-PMMA-b-PPhEtMA: BMP). BMP undergoes a hierarchical phase transition corresponding to the self-assembly of each of the thermosensitive blocks in the IL, and a sol-gel transition was observed in concentrated, above 10 wt %, polymer solutions. The gelation behavior was affected by polymer concentration, and at 20 wt %, the BMP/IL composite showed a phase transition, with increasing temperature, from solution through a jammed micelle suspension to a physically cross-linked gel. Each phase was formed reversibly and rapidly over the corresponding temperature range. The jammed micelle and cross-linked gel states were characterized using viscoelastic measurements and small-angle X-ray scattering (SAXS).</p>

Topics

• morphology
• phase
• composite
• phase transition
• copolymer
• small angle x-ray scattering
• self-assembly
• gelation