Relaxation dynamics of rubbed polystyrene thin films
Department of Physics and Liquid Crystal Institute Kent State University -
Kent, OH, USA
2 Department of Polymer Science, University of Akron - Akron, OH, USA
Accepted: 21 July 2000
Optical retardation measurements were used to probe the chain relaxation dynamics in rubbed polystyrene films of varying thicknesses on glass substrates. A model based on Kohlrausch-Williams-Watts relaxation was developed and used to determine the glass transition temperature of the films. Results showed reductions of 15–20 K in for thin films of thicknesses comparable to the radius of gyration as well as for cast films rubbed with different strengths. These results provide evidence of a faster relaxation dynamics relative to the polymer-substrate interface for thinner films and enhanced chain mobility at the polymer-air interface.
PACS: 68.60.-p – Physical properties of thin films, nonelectronic / 61.20.Lc – Time-dependent properties; relaxation / 64.70.Pf – Glass transitions
© EDP Sciences, 2000