Boosting the performance of long-chain polyamides

The insight

Polyamide 12 is a semi-crystalline polymer with a melting point of 178-180°C. It is prepared by a polycondensation/polyaddition reaction of laurolactam. The polymer offers a high toughness and ductility even at low temperature and high stress cracking resistance under chemicals. Compared to other nylons the polymer shows an extraordinarily low water absorption, that guarantees constant mechanical performance and dimensional stability. With a density of 1,01 g/cm³ Nylon 12 has the lightest material among the group of polyamides. The material offers excellent chemical stability and low coefficient of friction as well as high wear resistance. The material can be applied up to a continuous use temperature of 95-110°C (20000 hours).

The material can be reinforced with carbon or glass fibers. An additional material modification is possible by addition of solid lubricants (graphite, MoS2), conductive fillers (CNT, carbon black), softeners, impact modifiers, and nucleation aids.

Nylon 12 can be processed by injection molding, extrusion, fluidized powder bed coating, and selective laser sintering. Typical processing temperatures are between 180 and 220°C (injection molding) and 220°C and 270°C (extrusion).

The unique process of multi-layer tube extrusion enables to combine different materials and utilize specific properties of other polymers to develop satisfying solutions for the end-user.

Stabilization against hydrolysis and thermal degradation

Nylon 12 can be thermally stabilized by additive based either on sterically hindered phenolics or Cu+ ions (complexes with alkali metal salts promote the stabilizing effect of Cu+ ), these additive stabilize PA12 up to 150°C, carbodiimide based additives (e.g. STABAXOL® P 110) used to overcome hydrolysis efficiently. Carbon black in concentrations of 0,5-2 wt% or N-acylated sterically hindered amines (HALS)  are known for their proper UV stabilization.

Refractive Index

Transparent polyamide offers a refractive index of 1,52.

Novel use cases for long-chain polyamides

PA12 is available as UD tapes and organ sheets as well as other discontinuously reinforced composite materials, e.g. tapes are used in thermoplastic composite pipes (TCPs)