Thermal and oxidative degradation
Hydraulic fluids - Influencing factors

The thermal or pyrolytic stability of a chemical derivative is a fundamental property of the molecule in question, and few cases are known where it can be improved by an artifice such as the use of adjuvants. On the other hand, the thermal stability threshold can easily be lowered by the presence of foreign bodies, which may come from the preparation of the product, for example.

Oxidation stability is no longer linked to an intrinsic property of the molecule, but to a reaction between the molecule and oxygen. As such, it is sensitive to reaction conditions. Temperature plays an essential role, and it is generally accepted that the rate of reaction doubles with every 10°C increase in temperature. However, parameters such as air flow and air mixing in the fluid mass also have a significant influence. The reaction can also be influenced for good or ill: certain metals...