Spherulite formation in polyhexamethylene adipamide

Solid polyhexamethylene adipamide prepared by slow cooling of a melt is opaque as a result of formation of spherulites. Spherulites may also be formed by slow evaporation of a phenol solution of polyhexamethylene adipamide. Transparent, nonspherulitic polymer of a low degree of lateral order can be formed by cooling the polymer rapidly. Heat treatment or aging of this polymer increases the lateral order without the formation of microscopically visible spherulites. Spherulites usually reduce tensile strength, increase opacity, and decrease workability.