Common Names: Polyurethane, Urethane
Chemical Name: Polyester Urethane, Urethane
ASTM D1418 Designation: AU EU
ISO/DIN 1629 Designation: AU
ASTM D2000/SAE J200 Type, Class: BG
Description: Polyurethane is outstanding over most other O-ring elastomers in abrasion resistance and tensile strength.
Key Use(s): Seals for high hydraulic pressures. Situations where highly stressed parts are subject to wear.
Standard Compound: -35°C (-30°F) to 80°C (175°F)
Hardness (Shore A): 40 to 90
Features: Polyurethane offers superior seal performance in hydraulic situations, where high pressures, shock loads, or abrasive contamination is anticipated.
Polyurethane possesses chemical compatibility similar to that of Nitrile, offering good resistance to petroleum-based oils, hydrocarbon fuels and hydraulic fluids, the oxidizing effects of ozone, and the aging effects of sunlight. It also has good tear resistance.
Good low temperature flexibility is also a feature of many Polyurethane elastomer compositions.
Limitations: Unless specially compounded, at elevated temperatures Polyurethane begins to soften, losing its physical strength and chemical resistance advantages over other polymers.
Tending to rapidly deteriorate when exposed to concentrated acids, ketones, esters, chlorinated and nitro hydrocarbons, Polyurethanes are also prone to hot water and steam degradation.