What is Polyurethane?
Polyurethanes are synthesized polymers with very special features in rubber and plastic families. They can be soft as a gel or hard as a standard plastic material: all hardness can be possible.
Their general properties are much more advanced than any other competitive material.
You can find Polyurethane elastomers either in Thermoplastics or Thermohardening types.
Thermoplastic materials properties are already acquired when prepared as granule. Their design and shape can be modified then after under high temperature and pressure actions.
Thermohardening materials are liquid in ambient temperature. They acquire their properties when molding under temperature action which create a chemical reaction.
Thermoplastic elastomers are commonly called TPU and thermohardening are called PUR.
In all case, Polyurethane polymers are formed by reacting a monomer containing at least two isocyanate functional groups with another monomer containing at least two alcohol groups in the presence of a catalyst.
O
|
N = C = O + HO - donne - NH - C - O
PUR macromolecules are set up with various soft segments and hard segments which are linked in chain.