Polylactams (Nylon)

Properties and Applications

Polylactams are a family of synthetic aliphatic thermoplastic resins, produced via ring-opening polymerization of cyclic amides (lactams). The by far most important polylactam is polycaprolactam or Nylon 6 which accounts for almost one-third of all polyamides.1 It has excellent mechanical properties including high tensile strength, high flexibility, good resilience, high abrasion resistance, low creep and high impact strength. The good mechanical properties are retained over a wide temperature range due to its high melting point (495 K) and glass transition temperature. The heat deflection temperature of Nylon 6 exceeds those of polycarbonate and polyester. It is also easy to dye, exhibits excellent resistance to wear due to a low coefficient of friction (self-lubricating) and has good resistance to many chemical including oils, bases, and many solvents. The main limitations are strong moisture sensitivity (water acts as a plasticizer) and the resulting changes in dimensional and mechanical properties.

More than 60 percent of all aliphatic polyamides produced are used in commercial fiber applications. This includes carpets, garments, seatbelts, upholstery, ropes, and tire reinforcements. Textile products made from Nylon 6 are more resilient and durable than those made from polyesters but they are also more expensive. Nylon 6 resins, particularly glass reinforced and impact modified grades, are also important engineering materials. In fact, Nylon 6 is one the cheapest engineering plastics and finds applications in many industries and markets.

Manufacturers & Distributors

Companies

Brands

1Another commercially important polylactam is polydodecanolactam, also called polylaurolactam or Nylon 12. However, this resin is produced on a much smaller scale than Nylon 6.