Nylostab S-EED

The protection of polyamides against light has been an important objective. Clariant markets a sterically hindered amine, Nylostab S-EED, as a UV stabiliser and antioxidant for polyamides. 

Nylostab S-EED is an aromatic HALS used as a multi-functional additive in polyamides. Due to a novel chemical structure, it combines the effect of a light and heat stabilizer, resulting in flow improvement particularly in fibres, and its action in the improvement of colour strength with pigments and dyes. 

The selection of sterically hindered amines for light protection is also often determined by side-effects. In some cases, the side-effects are so significant that light protection almost becomes a secondary effect. For instance, Nylostab S-EED developed specifically for PA, is mainly used for its process stabilizing and color improving effects. Fig. 3.9 [510]. 

Polar ( engineering ) polymers being able to activate hydrogen bonds, for example, polyamides, can be efficiently stabilized by a multifunctional stabilizer N,N -bis-(2,2,6,6-tetramethyl-4-piperidyl) isophthalamide, commercially available under the trade name Nylostab S-EED (Figure 23). ... 

Nylostab S-EED fits well to polymers whose stmctures allow the molecule to be incorporated via hydrogen bonds, for example, polyamides (Figure 24). 

Major fields of application of this additive, typically used in a concentration between 0.1 and l.Owt.%, are thick section injection molded, even glass filled and/or pigmented resins, thin section fibers, monofilaments, films, and blow molded articles. Important benefits of Nylostab S-EED are improved thermo-oxidative and UV light stability enhanced output rates due to lowered and constant pressure during processing (see Figure 25), reduced cycle times and lower discoloration, respectively, nonstaining effects. Furthermore, this additive proteas colorants and provides better bleach resistance. 

Figure 24 Molecular incorporation of Nylostab S-EED into polyamide via H-bonds.

Figure 25 Stability of the polyamide melt processing in the presence of Nylostab S-EED during extrusion.

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