Polyamides are one of the most widely used engineering thermoplastic materials. They are melt processable thermoplastics characterised by a repeating amide linkage, and as engineering thermoplastics they offer a unique combination of high mechanical strength, low wear and abrasion properties together with good chemical resistance.

The aim of this review is to concentrate on the engineering thermoplastic uses of polyamide materials, thus focussing on injection moulding and extrusion applications, rather than the production of fibres and monofilaments for which polyamides were originally commercially developed. The dominance that polyamide 6 and polyamide 66 have within the nylon product sector is also reflected within the review. This report provides an excellent introduction to the topic of polyamides, outlining aspects from the basic chemistry and nomenclature through to the properties and applications of specific materials.

The types of polyamide available commercially today are described including polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 69, polyamide 610, polyamide 612, polyamide 46 and the aromatic polyamides. Polyamide copolymers such as polyamide 6,66, polyphthalamides and polyether block amides (PEBA) are also covered.

Polyamides can be modified in a variety of ways. During compounding a range of different additives can be included in formulations including flame retardants, plasticisers, stabilisers, lubricants, nucleants, fillers and reinforcement. Properties can also be improved by forming blends and these are discussed.

Polyamides are very sensitive to moisture and drying must be included in processing. The review highlights this and also covers injection moulding and extrusion, with regard to optimising the performance of polyamides.

Applications and markets are included in this overview. Polyamides are used in the automotive industry, the electrical and electronics industry, the packaging industry and the general engineering and construction industry.

Recycling is a major issue for most plastics processors in the new century. Polyamide recycling technology has been well studied and plants have been established for several years in different parts of the world. Both mechanical recycling and chemical recycling methods can be used.

This Rapra Review Report comprises a concise, expert overview, supported by an extensive bibliography of over 400 abstracts compiled from the Polymer Library on the topic of polyamides. This bibliography provides useful additional information. The majority of the papers cited date from the last five years, to provide up-to-date information on the latest applications, markets and producers, together with recent studies on material properties, processing and new types of polyamide.