VTF Equation
η = η₀·exp(A/(T−T₀))
T₀ = Kauzmann temperature
Fragility index m
m = d(log η)/d(Tg/T)|T=Tg
Strong: m≈16 (SiO₂)
Fragile: m>100 (o-terphenyl)
Kauzmann paradox: ΔS→0 at T₀
η = η₀·exp(A/(T−T₀))
T₀ = Kauzmann temperature
Fragility index m
m = d(log η)/d(Tg/T)|T=Tg
Strong: m≈16 (SiO₂)
Fragile: m>100 (o-terphenyl)
Kauzmann paradox: ΔS→0 at T₀