It is probably not an exaggeration to say that the development and commercialisation of linear, thermoplastic polyamides were due in large part to the farsightedness of the DuPont Company and the brilliance of Wallace H. Carothers. But from the beginning of nylon development, it was observed that under the action of heat or light, these aliphatic polyamides are susceptible to rapid discoloration, followed by loss of physical properties.