Nylon 66 Pellets: Nylon Salt Polymerised in an Autoclave, Carothers 1938

Nylon salt heated to 288 °C under oxygen-free nitrogen gives off water and joins into long chains of nylon 66 (Carothers, du Pont, US 2,130,948, 1938: two moles of salt in a silver-lined autoclave). A pinch of extra adipic acid keeps the melt's viscosity steady. The polymer is then extruded and cut into pellets. The picture: our drawing of the autoclave and the pellet line.