What is Polyurethane – PU rubber?

Polyurethane – PU is a polymer composed of a chain of organic units joined by carbamate (urethane) bonds. While most polyurethanes are thermosetting polymers that do not melt when heated, urethane elastomers are thermoplastic.

Polyurethane – PU elastomers are synthetic rubbers that can be subdivided into two categories:

  • Polyester urethane rubber – AU
  • Polyether urethane rubber – EU

Urethane rubber, whether polyester or polyether, can be classified as both an elastomer and a thermoplastic.

PU rubber – Resistance and flexibility

Polyurethane elastomers are synthetic rubbers with high mechanical strength, high elongation and excellent abrasion resistance. The maximum temperature to which this material can be exposed is 125°C. Polyurethane – PU rubber is used where wear resistance and high elasticity are required. Polyurethane rubber has high tensile and tear strength and is available in different Shore hardnesses.

Polyester Urethane Rubber – AU is resistant to abrasion, oils, fuels and ozone. It also has shock-absorption properties. It is characterized by slightly better water resistance than polyether urethane rubber – EU. Due to its many advantages, polyester urethane – AU rubber is used in many fields. It is used, for example, for the production of seals, particularly useful in hydraulics and pneumatics.

Summary of the properties of Polyurethane - PU rubber

Advantages

  • Good resistance to high pressures
  • Resistance to water, mineral oils and non-flammable liquids
  • Very good resistance to ozone
  • Good gas impermeability
  • Good level of mechanical properties
  • Operating temperature: -30°C to +125°C

Disadvantages

  • Low resistance to hot water and steam above 40°C
  • Low resistance to acids, amines and organic solvents

Applications of Polyurethane - PU rubber

PU rubber is widely used for hydraulic and pneumatic applications thanks to its properties of resistance to oils, wear, and its high mechanical resistance.

Brands of Polyurethane - PU rubber

Polyurethane – PU rubber is marketed under several brands, including the following:

  • Millathane®,
  • Urepan®