Rheological Analysis of Surface Relaxation Process of Monodisperse Polystyrene Films

DOI Web Site 64 Citations
  • Keiji Tanaka
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 812-8581, Japan
  • Atsushi Takahara
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 812-8581, Japan
  • Tisato Kajiyama
    Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 812-8581, Japan

Description

Surface glass transition temperature, , of monodisperse polystyrene (PS) films was determined from the temperature dependence of lateral force at a given scanning rate. The end groups of the PS were composed of sec-butyl group and a repeating unit terminated by proton. of the PS films was discerned to be markedly lower than its bulk Tg, , in the entire number-average molecular weight, Mn, range, 4.9K to 1460K. The Mn dependence of was analyzed on the basis of a simple power law. The exponent of Mn related to was −0.60 ± 0.03 in contrast to the power of −0.5 from the Mayes scaling argument that is based on both chain ends being perfectly localized at the surface. This result implies that the surface localization of end groups of the PS used here is not complete. The extrapolated to the infinite Mn was found to be lower than the corresponding by approximately 20 K. The apparent activation energy of the surface αa-relaxation process for the PS obtained from Arrhenius plot was 230 ± 10 kJ·mol-1, significantly...

Journal

  • Macromolecules

    Macromolecules 33 (20), 7588-7593, 2000-09-14

    American Chemical Society (ACS)

Citations (64)*help

See more

Details 詳細情報について

Report a problem

Back to top