Elongational Viscosity of Monodisperse and Bidisperse Polystyrene Melts
نویسندگان
چکیده
The startup and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 kg/mole and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongational rate, ǫ̇, of about two times 3η0 whereas the bidisperse melts have a maximum of up to a factor of 7 times the Trouton limit of 3η0. The Wiest model which incorporates anisotropic drag and finite extensibility may be used to interpret the results in molecular terms.
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