Polyhexamethylene adipamide

Waste nylon-6,6 was washed in a diluted commercial detergent solution at 100°C for 0.5 h and then rinsed twice with water to remove any finishes present. The washed nylon-6,6 was then reacted with molten adipic acid for 1.5 h or more at a temperature of 175°C with a weight ratio of nylon-to-adipic acid of 0.15 1. The molten product was then exposed to steam at a temperature of 230-233°C to remove any stabilizers present. The acidolysis product was then hydrolyzed with water at a temperature of 204°C under autogenous pressure for 0.5 h or longer with a ratio of water to acidolysis product of 0.50 1 (w/w). The hot solution was then filtered at 100°C to remove any titanium dioxide present. The filtered product was then mixed with HMDA to neutralize any excess acid present. The solution was then filtered to remove any solids. A 50% by weight aqueous solution of HMDA was added to the filtrate, and under standard polymerization conditions, polyhexamethylene adipamide (nylon-6,6) was produced. 

On February 28, 1935, Carothers project succeeded beyond anyone s wildest dreams. The cheerful, lively Frenchman Berchet produced a superpolymer made from chemicals derived from cheap benzene, a by-product of coal later they would be made from petroleum. A filament teased from Berchet s polymer was, despite its lowly origins, pearly and lustrous. And when it was tested, it proved to be spinnable. Its code name was 6-6 because both its reactants—hexamethylene diamine and adipic acid—had six carbon atoms. Technically, the filament was polyhexamethylene adipamide, a long-chain polymer similar in structure to proteins. It became world-famous as nylon. 

Wilhoit, R. C., and M. Dole Specific heat of synthetic high polymers. II. Polyhexamethylene adipamide and sebacamide. J. Phys. Chem. 57, 14 — 21 (1953). 

An additional, important, type of chain polymers is the polyamides, polyesters, and polyurethanes [195-197], Among the polyamides, nylon is a very important member. In Figure 2.38, the repeating unit of one of the member of the nylon family, that is, the repeating unit of polyhexamethylene adipamide, or nylon 6,6 is represented [8,195]. As was previously commented, nylon is applied in stockings, ropes, fabrics, and has other uses. 

McLaren, J. V. A kinetic study of the isothermal spherulitic crystallization of polyhexamethylen adipamide. Polymer 4, 175—189 (1963). 

Nylon 66. The word nylon was established as a generic name for polyamides, one class of the new high molecular weight linear polymers. The first of these, and the one still produced in the largest volume, was nylon 66 or polyhexamethylene adipamide. Numbers are used following the word nylon to indicate the number of carbon atoms contributed by the diamine and dicarboxylic acid constituents, in this case hexamethylenediamine and adipic acid, respectively. 

Polyhexamethylene adipamide Poly(hexamethylene adipamide) Poly(iminohexamethylene iminoadepoly)... 

Some nine years ago, Ellison and Zisman [4] reported their study of the wettability of 6-6 nylon (polyhexamethylene adipamide) and compared their results to those previously obtained on polyethylene [7]. They found that the nylon was more easily wet than the polyethylene, especially by hydrogen-bonding liquids, and attributed these findings to the presence of amide groups in the nylon surface. 

The melting temperature vs. composition data for the polyhexamethylene sebacamide/terephthalamide copolymers reported in the following text show the expected minimum, but this is not the case for the polyhexamethylene adipamide/terephthalamide copolymers (Edgar and Hill, 1951). Construct a plot of melting temperature vs. copolymer composition. With reference to the polymer chemical structures, explaiu the diffraent trends observed for the sebacamide and adipamide data. 

Polyhexamethylene Adipamide/Terephthalamide Copolymers Polyhexamethylene Sebacamide/Terephthalamide Copolymers ... 

V V Korshak, G L Slonimskii and E S Krongauz, Hetero-chain polyamides. VII - thermal destruction of polyhexamethylene adipamide , Izvest Akad Nauk SSSR, Otdel Khim Nauk 1958, 221. 

Fig. 70. Low angle deflection X-ray photographs of polyhexamethylene adipamide, borrowed from Hess and Kiessig.

LONG FIBRE SPACINGS IN POLYHEXAMETHYLENE ADIPAMIDES OF VARYING AVERAGE CHAIN LENGTH... 

From electron diffraction experiments it could be derived that the dimension of the crystallites in polyhexamethylene adipamide is roughly in the order of 100 A,... 

It is of considerable interest, that polyhexamethylene adipamide, prepared by condensation in a solvent like xylenol and then precipitated in powder form, does not show long range periodicity, neither do fibres spun from a xylenol solution in an alcohol bath (Hess and Kiessig). The fibres obtained have a low tensile strength and are brittle. These objects are obviously formed in the gel condition at ordinary temperature and then exhibit less favourable properties. These facts are important with regard to regenerated cellulose. 

Copolyamide of 60 % polyhexamethylene adipamide and 40 % polyhexamethylene adipamide-terephlhamide/ EP-g-MA Melt extmsionAnechanical properties Neilinger et al. 1988... 

PA-66 Poly(hexamethylene diamine-adipic acid), polyhexamethylene-adipamide PA-6IT6 Poly(caprolactam-co-hexamethylene diamine-isophthalic/terephthalic... 

The only case of textile dermatitis reported to be caused by fiber polymers during the 1990s was that described by Tanaka et al. (1993). In this case, the specific nylon polymer was epsilon-aminocaprioic acid (EACA). This is not one of the usual polymers used to form nylon those polymers being polyhexamethylene adipamide for nylon 66 fibers and polycaproamide for nylon 6 fibers. 

Fig. 132. Dependence of the load on the elongation for nonirradiated and irradiated polyhexamethylene-adipamide fiber. 1) Nonirradiated fiber 2) irradiated in nitrogen for 96 hr at 40°C 3) the same, in air 4) the same, in oxygen.

Fig. 135. Spectra of films of the copolymer of polycapro-amide, polyhexamethylene-adipamide, and polyhexamethyl-enesebacamide. 1) Before irradiation 2) directly after irradiation in air for 80 hr 3) irradiated film 2 after storage in the dark for 24 hr D) optical density.

Common names nylon-6,6, polyhexamethylene adipamide CA number [32131-17-2]... 

Figure 6-10 shows some typical curves for 66 nylon (polyhexamethylene adipamide) for temperatures well below the polymer s melting point. 

C12H22N2O2, Polyhexamethylene adipamide (nylon 6.6), 11, 591 Cl3H14NO2, Poly(1,2-bis(4-(phenylcarbamoyloxy)-n-butyl)-1 buten-3 ynylene), 44B, 1103... 

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