Trogamide

Nylon staple Nylon trogamid Nylon-wool blends Nypel... 

Commercial engineering thermoplastic nylons are mainly crystalline resins. Nylon-6,6 [32131 -17-2] is the largest volume resin, followed by nylon-6 (48). Other commercially available but much lower volume crystalline nylons are -6,9, -6,10, -6,12, -11, and -12. The crystallinity of the molded part decreases with chain size (49). A few truly amorphous commercial nylon resins contain both aromatic and ahphatic monomer constituents (50). For example, Trogamid T resin is made from a mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamines and terephthahc acid (51). 

Property ASTM method Nylon-6,6 Zytel Nylon-6 Zytel —. be 211 Trogamid T ... 

The oldest of these materials, a poly (trimethylhexamethylene terephthal-amide) was first marketed by Dynamit Nobel in the mid-1960s (Trogamid T). It is a condensation product of trimethylhexamethylenediamine and terephthalic acid (or its dimethyl ester) (Figure 18.25). In practice a 1 1 mixture of 2,2,4- and 2,4,4-trimethyldiamines is used, this being produced from acetone via iso-phorone, trimethyladipic acid and trimethyladiponitrile. 

The mechanical properties for Trogamid T are for dry material at 20 C those for Grilamid TR-55 at standard atmosphere at 23 C. This will account, in part, for the differences in the figures for mechanical properties of the two polymers. 

Of the transparent polyamides the Grilamid material has the lowest density and lowest water absorption. It is also claimed to have the best resistance to hydrolysis, whilst transparency is unaffected by long-term exposure to boiling water. Tbe properties of Trogamid T and Grilamid TR55 are compared in Table 18.11. 

In addition several other materials have been reported by industrial companies, but have not at the time of writing been commercialised. These include the product of condensation of 2,2-bis-(p-aminocyclohexyl)propane (VI) (Figure 18.28) with a mixture of adipic and azelaic acid (Phillips Petroleum), a research material produced in the old German Democratic Republic obtained by melt condensation of /ranj -cyclohexane-l,4-dicarboxylic acid (VII) (Figure 18.28) and the two trimethylhexamethylenediamine isomers used in the manufacture of Trogamid T, and another amorphous material (Rilsan N by Ato Chimie). 

Amodel, Grilamid, Ixef, Laramid,Trogamid, Zytel HTN. 

In nylon 6 and nylon 6/6 practically all NH groups are bound by hydrogen bridges. In Trogamid T and other experimental samples there are many more free NH groups. However, the total free NH groups may be below 5% (3). 

This product was first reported in 1966 (4). Since then, knowledge has been widened through the studies of W. Pungs and J. Schneider. Here only a general characterization is given. Contrary to the classical nylons, Trogamid is a clear material, similar to polycarbonate. 

The expansion coefficient is also similar to that of polycarbonate, and the same is true for the torsional modulus vs. temperature as shown in Figure 2. Trogamid T has a good tensile strength (ca. 500 kg.) even at temperatures as high as 100 °C. 

Electrical Properties. In its electrical insulating properties Trogamid T is similar to other polyamides. Its dielectric properties are not particularly striking. The electrical properties undergo slight change in relation to humidity, and prolonged water immersion has no appreciable... 

Behavior in Water and Aqueous Solutions. Like all polyamides Trogamid T absorbs water when stored in humid air or immersed in water. This absorption, however, is lower than that of nylon 6 and nylon 6/6 (Figure 3 and Table X). 

In the different polyamides the absorbed water has the following apparent density nylon 6 = 0.86, Rilsan = 0.72, Trogamid = 0.67. Immersion in water up to 80 °C. has little influence on the properties. In boiling water, however, turbidity is observed, and this is especially evident in a thin film. An alkaline pH adjustment of the hot water reduces this phenomenon. The turbidity is not accompanied by degradation. Dried turbid material can be processed to clear specimen. Electronic... 

Trogamid T can be processed without difficulty by the normal methods used for thermoplastics (5). In this respect it offers fewer problems than polyacetal or polycarbonate, for example. Some Trogamid T properties can be improved by biaxial orientation. The effects, however, are lower than with crystalline polymers. 

Trogamid T has low mold shrinkage and good dimensional stability. The weldability which is very good offers an obvious advantage over the crystalline polyesters and polyamides. 

Mechanical properties (stiffness, impact, and shock resistance), electrical properties, clarity, ease of processing, sealing properties, dimensional stability, resistance to hydrocarbons and other organic liquids, resistance to plasticizers, greases, and oils are the characteristic properties desired. In its mechanical properties it approaches polycarbonate most closely. However, since polycarbonate is cheaper than Trogamid T, Trogamid T will be preferred only where polycarbonate cannot be used. 

Typical applications for Trogamid T are flow meters or flow meter parts for gases and liquids, containers, parts in electrical equipment and appliances, optical equipment, measuring devices, printing machines. 

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