1. History

In 1849, Würtz was the first to use a reaction between a glycol and an isocyanate, but it was Otto BAYER, in 1937, who discovered how to transform the resulting product into a usable plastic.

This material was first used in times of war and blockade to obtain substitutes for synthetic fibers (nylon in particular) and natural rubber (see Box 1 ). Then, when the expansion reaction between water and isocyanate was demonstrated, the chemical industry quickly obtained rigid and flexible foams. Under the impetus of American (DuPont de Nemours, Wyandotte) and European (Bayer, ICI, etc.) companies, developments for the manufacture of rigid and flexible foam blocks and molded parts based on TDI isocyanate gained in importance.