Polyadipyladipylenediamine, commonly known as nylon -66, is a thermoplastic resin, generally made from adiponic acid and hexadipamine condensation. Insoluble in general solvents, only soluble in m-cresol, etc. High mechanical strength and hardness, rigidity. It can be used as engineering plastics, mechanical accessories such as gears, lubricating bearings, instead of non-ferrous metal materials to make machine shells, automotive engine blades, and can also be used to make synthetic fibers.

Polyamide plastic products are widely used in a variety of mechanical and electrical parts, including bearings, gears, pulley pump impeller, blade, high pressure sealing ring, cushion, seat, bushing, oil pipeline, storage device, rope, transmission belt, grinding wheel adhesive, battery box, electrical coil, cable joint, etc. There is also a large amount of packaging tape and food film (high temperature film for cooked food and low temperature film for cool drinks). The United States Monsanto company developed for reaction injection molding polyamide plastic, also known as RIM nylon, is very popular in many countries, some countries made glass reinforced RIM nylon large automobile shell parts, so that polyamide in the competition with metal materials, in the automobile manufacturing industry to reduce weight, energy saving and reduce costs to find another way.