The differential isoconversional method of Friedman is based on the Arrhenius equation:

f (α): the model function

A: the pre-exponential factor

E: the activation energy

T: the temperature

t: the time

Friedman has applied the logarithm of the conversion rate d α /dt as a function of the reciprocal temperature at any conversion α:

As f(α) is a constant in the last term at any fixed α, the logarithm of the conversion rate d α /dt over 1/T shows a straight-line dependence with the slope of m = -E/R.

By the extension of the expression

with

one can predict the reaction rate or reaction progress having determined  and using the following expression:

Prediction of the oxidation reaction rate using the Arrhenius equation for isothermal temperature profiles: shelf life of unstabilised natural rubber from 4 to 28°C.
isothermal prediction
Prediction of the oxidation reaction rate using the Arrhenius equation for modulated temperature profiles (dT = 20°C with 0..7 K modulation per 24h).
modulated temperature prediction
Prediction of the oxidation reaction rate using the Arrhenius equation of unstabilised natural rubber in world climate conditions (Las Vegas, Tokyo, Zürich und Calgary).
world climate prediction

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