Surface segregation of chain ends in α,ω-fluoroalkyl-terminated polystyrenes films

Keiji Tanaka, Daisuke Kawaguchi, Yasuyuki Yokoe, Tisato Kajiyama, Atsushi Takahara, Seiji Tasaki

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

α,ω-Fluoroalkyl-terminated polystyrenes (α,ω-PS(Rf)2) with various molecular weights were synthesized by an anionic polymerization. Then, chain end distribution in the surface region of the α,ω-PS(Rf)2 films was studied by angular-dependent X-ray photoelectron spectroscopy in conjunction with neutron reflectivity. The α,ω-PS(Rf)2 films annealed under vacuum exhibited surface localization of chain ends. Since the fluoroalkyl chain ends possess a lower surface free energy compared with the main chain part, they energetically prefer to partition to the surface. The extent to which the chain ends were segregated at the surface was examined as a function of molecular weight. Also, it was presented how surface orientation of the fluoroalkyl end groups was dependent on molecular weight. On the other hand, no segregation of the chain ends was observed at the surface of the α,ω-PS(Rf)2 film annealed in boiled water. This is because the chain ends with a lower surface free energy tend to stay away from the higher energy medium of the boiled water. This result reveals that the surface concentration of chain ends can be regulated by selecting an appropriate annealing condition based on surface thermodynamics.

Original languageEnglish
Pages (from-to)4171-4177
Number of pages7
Journalpolymer
Volume44
Issue number15
DOIs
Publication statusPublished - Jun 27 2003

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All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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