Quantifying the elasticity and viscosity of geometrically confined polymer films via thermal wrinkling |
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| Authors: | Edwin P Chan Qinghuang Lin Christopher M Stafford |
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| Institution: | 1. Polymers Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899;2. IBM T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 |
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| Abstract: | We apply thermal wrinkling, which is a surface instability that occurs during thermal annealing of polymer films geometrically confined by a rigid substrate and a flexible superstrate, to study the elasticity and viscosity of chemically crosslinked polymer systems. Specifically, we study the thermal wrinkling of aluminum‐capped polyhydroxystyrene films with different extent of chemical crosslinking and find that that the rate of change of the wrinkling wavelength with annealing time and temperature has unique relationships with the elasticity and viscosity of the polymer network. With the aid of analytical expressions that relate the time‐ and temperature‐dependent evolution of the wrinkle wavelength to the elasticity and viscosity, we are able to quantify the elastic modulus and shear viscosity of geometrically confined polymer thin films as a function of the degree of crosslinking. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 |
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| Keywords: | mechanical properties networks relaxation stress stress relaxation surface wrinkling thin films viscoelastic properties |
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