Terephthalamide

A process for the commercial synthesis of -phenylene diisocyanate using terephthalamide [3010-82-0] as a precursor and involving N-halo intermediates has been studied extensively (21). The synthesis of 1,4-diisocyanatocyclohexane from terephthaUc acid [100-21-0] also involves a nitrene intermediate (22). 

Figure 4.J2. Melting points of copolymers of hexamethyleneadipamide and -terephthalamide, and of hexamethylenesebacamide and -terephthalamide. (After Edgar and Hill )...

N,N -Dimethy l-ZV.A -dinitrosoterephthalamide (V) Terephthalamide N2,H20, CO2 90-105 180 Low exotherm on decomposition but low decomposition temperature restricts use largely to open-cell foams. 

Fibers in which the basic chemical units have been formed by chemical synthesis, followed by fiber formation, are called synthetic fibers. Examples include nylon, carbon, boron fibers, organic fibers, ceramic fibers, and metallic fibers. Among all commercially available fibers, Kevlar fibers exhibit high strength and modulus. (Kevlar is a DuPont trademark for poly [p-phenylene diamine terephthalamide].) It is an aromatic polyamide (aramid) in which at least 85% of the... 

Acid chlorides are very reactive and at room temperature react readily with amines. Synthesis by interfacial and solution methods is possible. However, care should be taken that the hydrochloric acid produced does not react with unreacted amine groups. With the strong basic aliphatic diamines, the acid binder must preferably be even more basic. The attainable molecular weights are strongly dependent on the concentrations this is particularly the case for easily precipitated terephthalamide polymers. Possible problems with the acid binder can be overcome by starting with silylated diamines.33,34 A typical example for interfacial polymerization of terephthalamides is PA-2,T.66... 

Example 18. Polyfp-phenylene terephthalamide) from terephthaloyl chloride.69... 

Example 20. Poly(p-phenylene terephthalamide) by silylated diamines.33... 

Figure 16 Chain structure of poly(p-phenylene terephthalamide) (Kevlar ).

The terephthalamide moiety (Fig. 13) is similar in structure to catechol, but has a higher affinity for iron(III) at physiological conditions and consequently has been used in the synthesis of siderophore mimics. The higher pFe values are due to the... 

Fig. 13. A series of bidentate terephthalamide-based siderophores with differently charged substituents.

See also 3,4 -Diaminodiphenyl ether (3,4 ODA) ODA/PPTA fibers Polyfp-phenylene terephthalamide) (PPTA) commercial process for, 19 721-723 wet spinning of, 19 725 Copolyfp-phenylene sulfide sulfone/ ketone) s, 23 710... 

Diaminodiphenyl ether (3,4 ODA), 19 715. See also Copoly(p-phenylene/ 3,4 -diphenyl ether terephthalamide) (ODA/PPTA)... 

Poly(p-phenylene sulfide ketone), 23 709 Poly(p-phenylene terephthalamide),... 

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