1. PA 6-6 overview

1.1 Industrial development

Polyamides originated with polyamide 6-6, first prepared by W.H. Carothers in 1935 from adipic acid and hexamethylenediamine, then launched by Du Pont de Nemours in 1938 as a fully synthetic textile filament under the name Nylon. Polyamides quickly became widely used in textiles.

Around 1941, Nylon began to be marketed as a molding powder for plastics. Its crystalline nature provided :

• on the one hand, a different behavior during transformation: very rapid transition from the solid to the molten state, contrary to what happens with polystyrene or polymethyl methacrylate, for example (amorphous polymers);

• higher mechanical properties (rigidity, hardness,...