The Evolution of Interfacial Strength as a Way to Characterize a Low-Temperature Limit of the Surface Glass Transition of an Amorphous Polymer |
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Authors: | Yuri M Boiko |
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Institution: | Laboratory of Physics of Strength, A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences , St. Petersburg, Russia |
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Abstract: | The evolution of autoadhesive strength, σ, with healing temperature, T h, at the symmetric amorphous polystyrene (PS)?PS interfaces of the samples with vitrified bulk has been used to characterize a low-temperature limit of the surface glass transition temperature T g surface(low). The existence of a linear relationship between the square root of σ and T h has been found for both polydisperse and monodisperse polymers. By the extrapolation of straight lines σ 1/2 ? T h to σ 1/2 = 0, the values of T g surface(low) have been determined and compared with those of a high-temperature limit of T g surface, T g surface(high), measured earlier. The differences between T g surface(low) and T g surface(high) have been found to be insignificant, 10–20°C. Using an average value of the shift of T g surface(low) with healing time, t h, the quasi-equilibrium value of the surface glass transition temperature of amorphous PS T ∞ surface has been estimated to be 10–15°C. |
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Keywords: | amorphous polystyrene interfacial strength surface glass transition |
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