The term “nylons” refers to the group of plastics known as polyamides. Nylon is used in the production of film and fibre, but is also available as a moulding compound.
There are many types of nylon available, including nylon 6, nylon 66, nylon 6/6-6, nylon 6/9, nylon 6/10, nylon 6/12, nylon 11 and nylon 12. The material is available as a homopolymer, co-polymer or reinforced. Nylons may also be blended with other engineering plastics to improve certain aspects of performance. Nylon is well suited for processing via injection moulding, rotational moulding, casting, or extrusion into film or fibre.
Chemical Composition
Its properties are determined by the R and R′ groups in the monomers. In nylon 6,6, R′ = 6C and R = 4C alkanes, but one also has to include the two carboxyl carbons in the diacid to get the number it donates to the chain.
Also Known As
Polyamides, PA.
Properties
The majority of nylons tend to be semi-crystalline and are generally very tough materials with good thermal and chemical resistance. The different types give a wide range of properties, with specific gravity, melting point and moisture content tending to reduce as the nylon number increases. Nylons can be used in high temperature environments; heat stabilized systems allow sustained performance at temperatures up to 185 °C.
| Property | Value |
|---|---|
| Tensile strength | 90–185 N/mm2 |
| Notched impact strength | 5.0–13.0 kJ/m2 |
| Thermal coefficient of expansion | 80 × 10-6 |
| Max. continued use temperature | 150–185 °C (302–365 °F) |
| Melting point | 190–350 °C (374–662 °F) |
| Glass transition temp. (nylon 66) | 45 °C (113 °F) |
| Density | 1.13–1.35 g/cm3 |