
HZO explores how the temperature limitations of Parylene coatings depend mainly on two factors: the type of Parylene used and the environment in which it is applied.
In an oxidizing environment, such as exposure to air, Parylene will become brittle and crack when heated.
Parylene N becomes brittle and cracks at around 70–80°C under Earth’s atmosphere. Parylene C has better thermal resistance, with brittleness and cracking occurring around 120–125°C. Parylene F, also known as Parylene VT4, withstands temperatures at or greater than 250°C before becoming brittle.
When Parylene is used in an inert environment, such as under argon or nitrogen, it can tolerate much higher temperatures. In these conditions, service temperatures greater than 200°C are achievable for all types of Parylene.