Time-temperature superposition in viscous liquids

Dielectric relaxation measurements on supercooled triphenyl phophite show that time-temperature superposition (TTS) is obeyed fur the primary relaxation process at low temperatures. Measurements on other molecular liquids close to the calorimetric glass transition indicate that TTS is linked to an omega (-1/2) high-frequency decay of the loss, while the loss peak width is nonuniversal.