Quantifying Water Vapor Diffusion across Elastomer Pressure Sensor Seals
Water vapor diffusion across elastomer seals causes reference cavity pressurization and dielectric drift, requiring coulometric ISO 15105-2 verification.
Hydrogenated Nitrile
Synthetic Elastomer
An elastomeric polymer provides superior resistance to heat and chemicals by saturating the carbon backbone of a nitrile rubber through a catalytic process. Using hydrogenated nitrile in sealing applications allows for higher operating temperatures than standard nitrile while maintaining excellent mechanical properties. This material excels in environments containing aggressive oils and sour gas where standard rubbers would become brittle or swell excessively.
Its performance is limited by high cost and a loss of flexibility at extremely low temperatures.
Chemical Resilience
The saturation of the polymer chain reduces the number of double bonds available for oxidation or ozone attack. Because of this structural stability, hydrogenated nitrile retains its tensile strength and abrasion resistance over long periods of exposure to hot fluids. It is frequently specified for downhole tools and automotive timing belts where reliability is a priority.
The material also demonstrates high resistance to explosive decompression in high pressure gas systems.
Processing Requirement
Compounding this polymer requires specific curing agents to achieve the desired crosslink density for a given application. Peroxide curing typically yields better heat resistance than sulphur curing for hydrogenated nitrile components.
Qualification Metric
Hardness and compression set are the primary indicators of material quality during the procurement process. Standardized tests like ASTM D2000 define the performance grades available for different industrial uses. Each batch is verified through laboratory analysis to ensure the degree of hydrogenation meets the specification for the intended environment.