Viscoelastic behavior of 1,3,5 tri #alpha#-naphthyl benzene (will the real T#alpha#NB please stand up)

摘要

The mistaken identity of 1,3-bis (1-naphthyl)-5-(2-naphthyl) benzene (1,3#alpha#-5#beta# TNB throughout the article) for 1,3,5-tris (1-naphthyl) benzene (T#alpha#NB throughout the article) is acknowledged and viscosities and recoverable creep compliances above T_g for the real T#alpha#NB are reported. In addition, semicontinuous creep measurements have been carried out below T_g while time dependent structural changes occurred as the material drifted towards an equilibrium state, following temperature decreases ("down jump") and increases ("up jump"). With this new measurement scheme, the evolution of both viscosity and recoverable creep compliance can be followed during the isothermal and isobaric drifts toward equilibrium. Since the steady state creep compliance of T#alpha#NB is nearly independent of temperature in the temperature range from 61.8 to 72.4 deg C, the recoverable compliance curves did not change shape with changes in temperature; i.e., thermorheologically simple behavior was observed.