Surface thermal molecular motion of chain end-modified polystyrenes

Tisato Kajiyama, Keiji Tanaka, Atsushi Takahara

研究成果: ジャーナルへの寄稿記事

7 引用 (Scopus)

抄録

Surface glass transition temperature, Tgs, of three classes of monodisperse polystyrene, proton-terminated (PS-H), α,ω-diamino-terminated (α,ω-PS(NH2)2) and (α,ω-dicarboxy-terminated (α,ω-PS(COOH)2), were studied by scanning force microscopy. Tgs of all samples was discernibly lower than the corresponding bulk glass transition temperature, Tgb. Also, Tgs value was strongly dependent on what the chemical structure of chain end groups was. Based on the time-temperature superposition principle, apparent activation energy of the αarelaxation process corresponding to surface segmental motion was evaluated to be approximately 230 kJ•mol-1. This value was much smaller than the reported bulk ones, and was independent of the chemical structure of chain ends. This result implies that the cooperativity for the αa-relaxation process at the PS surface is reduced in comparison with the bulk due probably to an existence of the free space presented to polymer segments at the surface. Hence, it was concluded that the surface αa-relaxation process was activated by not only the chain end effect but also the reduced cooperativity at the surface.

元の言語英語
ページ(範囲)265-270
ページ数6
ジャーナルMacromolecular Symposia
192
DOI
出版物ステータス出版済み - 3 1 2003

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Polystyrenes
polystyrene
Relaxation processes
glass transition temperature
Hot Temperature
Protons
Atomic force microscopy
Polymers
Activation energy
activation energy
microscopy
Hydrogen
scanning
protons
polymers

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

これを引用

Surface thermal molecular motion of chain end-modified polystyrenes. / Kajiyama, Tisato; Tanaka, Keiji; Takahara, Atsushi.

:: Macromolecular Symposia, 巻 192, 01.03.2003, p. 265-270.

研究成果: ジャーナルへの寄稿記事

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