The term polyurethane encompasses a vast family of products with the most varied characteristics in terms of mechanical, chemical and physical properties.
Through the correct choice and proportion of polyols and diisocyanates it is possible to pass from soft and fluffy products, such as very low density flexible foams (cushions, mattresses, etc.), to products with high resistance to compression and bending stresses for sports applications such as hiking, skiing etc.
The main distinction to be taken into consideration, in order to have a guideline, on the characteristics of polyurethane concerns its chemical nature, i.e. whether it is an ester or ether base.
On the market there is also a third family of polyurethane deriving from the synthesis of caprolactone which has intermediate characteristics between polyester and polyether.