Abstract

Polyamides (nylons) are important engineering plastics as well as being well known for fiber applications. This article covers the properties, manufacture, processing, and use of polyamide plastics together with information on specifications, sales, and suppliers. Materials discussed include nylon-6,6, nylon-6, nylon-6,9, nylon-6,12, nylon-11, nylon-12, nylon-4,6, amorphous nylon, and other semiaromatic nylons. Physical properties described are crystallinity, thermal properties, moisture absorption, electrical properties, and flammability. Chemical properties are hydrolysis/polycondensation, thermal degradation, oxidation, uv aging, and effect of chemicals and solvents. Manufacture is described including solid-state polymerization, compounding, and pultrusion. Compounding also includes a review of additives and modifications covering lubricants, nucleants, stabilizers, impact modifiers, flame retardants, plasticizers, reinforcements, nanocomposites, and polymer blends. The following processing routes are detailed: injection molding, extrusion, film, tubing and pipe, monofilament, rods and profiles, wire and cable coating, blow molding, rotomolding, reaction injection molding, powder coating, and also assembly techniques. Economics and recycling issues are discussed. Specifications, standards, and quality control are also reviewed with an indication of appropriate test methods.