Nylon naming

Polyamides from diamines and dibasic acids. The polyamides formed from abphatic diamines (ethylene- to decamethylene-diamine) and abphatic dibasic acids (oxabc to sebacic acid) possess the unusual property of forming strong fibres. By suitable treatment, the fibres may be obtained quite elastic and tough, and retain a high wet strength. These prpperties render them important from the commercial point of view polyamides of this type are cabed nylons The Nylon of commerce (a 66 Nylon, named after number of carbon atoms in the two components) is prepared by heating adipic acid and hexamethylenediamine in an autoclave ... 

This oxime rearranges under acidic conditions to a seven-mernbered cyclic amide icaprolactam, that is the monomer used in making one of the must widely used types of nylon, namely nylon-6. A more specialized polyamide, nylon-T 2. is made in a similar way from cyclododecane (5.82) this polymer finds applications in coating metals and in making plastic components for motor cars. 

We only need to recall the trade name of synthetic polyamides, nylon, to recognize the importance of these polymers and the reactions employed to prepare them. Remember from Sec. 1.5 the nylon system for naming these... 

Other elastomeric-type fibers iaclude the biconstituents, which usually combine a polyamide or polyester with a segmented polyurethane-based fiber. These two constituents ate melt-extmded simultaneously through the same spinneret hole and may be arranged either side by side or ia an eccentric sheath—cote configuration. As these fibers ate drawn, a differential shrinkage of the two components develops to produce a hehcal fiber configuration with elastic properties. An appHed tensile force pulls out the helix and is resisted by the elastomeric component. Kanebo Ltd. has iatroduced a nylon—spandex sheath—cote biconstituent fiber for hosiery with the trade name Sidetia (6). 

The nomenclature (qv) of polyamides is fraught with a variety of systematic, semisystematic, and common naming systems used variously by different sources. In North America the common practice is to call type AB or type AABB polyamides nylon-x or nylon-respectively, where x refers to the number of carbon atoms between the amide nitrogens. For type AABB polyamides, the number of carbon atoms in the diamine is indicated first, followed by the number of carbon atoms in the diacid. For example, the polyamide formed from 6-aminohexanoic acid [60-32-2] is named nylon-6 [25038-54-4], that formed from 1,6-hexanediamine [124-09-4] or hexamethylenediamine and dodecanedioic acid [693-23-2] is called nylon-6,12 [24936-74-1]. In Europe, the common practice is to use the designation "polyamide," often abbreviated PA, instead of "nylon" in the name. Thus, the two examples above become PA-6 and PA-6,12, respectively. PA is the International Union of Pure and AppHed Chemistry (lUPAC) accepted abbreviation for polyamides. 

Because the rules for organic nomenclature determine the priority of naming different carbon chains from their relative lengths, the systematic names for type AABB polyamides depend on the relative length of the carbon chains between the amide nitrogens and the two carbonyl functions of the polymer for aUphatic nylon-Ayy, when x < the lUPAC name is poly[imino-R imino(l2y-dioxo-R )]. When x > then the name is... 

Nylon-11. Nylon-11 [25035-04-5] made by the polycondensation of 11-aminoundecanoic acid [2432-99-7] was first prepared by Carothers in 1935 but was first produced commercially in 1955 in France under the trade name Kilsan (167) Kilsan is a registered trademark of Elf Atochem Company. The polymer is prepared in a continuous process using phosphoric or hypophosphoric acid as a catalyst under inert atmosphere at ambient pressure. The total extractable content is low (0.5%) compared to nylon-6 (168). The polymer is hydrophobic, with a low melt point (T = 190° C), and has excellent electrical insulating properties. The effect of formic acid on the swelling behavior of nylon-11 has been studied (169), and such a treatment is claimed to produce a hard elastic fiber (170). 

A number of high melting poiat semiaromatic nylons, iatroduced ia the 1990s, have lower moisture absorption and iacreased stiffness and strength. Apart from nylon-6 /6,T (copolymer of 6 and 6,T), the exact stmcture of these is usually proprietary and they are identified by trade names. Examples iaclude Zytel HTN (Du Pont) Amodel, referred to as polyphthalamide or PPA (Amoco) and Aden (Mitsui Petrochemical). Properties for polyphthalamide are given ia Table 2. A polyphthalamide has been defined by ASTM as "a polyamide ia which the residues of terephthaUc acid or isophthahc acid or a combination of the two comprise at least 60 molar percent of the dicarboxyhc acid portion of the repeating stmctural units ia the polymer chain" (18). 

Nylon-6 [25038-54-4] (9) is made by the bulk addition polymerization of caprolactam. Monofilament Nylon-6 sutures are avadable undyed (clear), or in post-dyed black (with logwood extract), blue (ED C Blue No. 2), or green (D C Green No. 5). Monofilament nylon-6 sutures are sold under the trade names Ethilon and Monosof monofilament nylon-6,6 sutures, under the trade names Dermalon and Ophthalon and monofilament polyethylene terephthalate sutures, under the trade name Surgidac. 

Acid Dyes. These water-soluble anionic dyes ate appHed to nylon, wool, sUk, and modified acryHcs. They ate also used to some extent for paper, leather, food, and cosmetics. The original members of this class aU had one or mote sulfonic or catboxyHc acid groups in thein molecules. This characteristic probably gave the class its name. Chemically, the acid dyes consist of azo (including preformed metal complexes), anthraquiaone, and ttiaryHnethane compounds with a few azHie, xanthene, ketone imine, nitro, nitroso, and quHiophthalone compounds. 

At temperatures 50°C or so below T, thermoplastics become plastic (hence the name). The stress-strain curve typical of polyethylene or nylon, for example, is shown in Fig. 23.10. It shows three regions. 

Copolymers of chlorotrifluoroethylene and ethylene were introduced by Allied Chemicals under the trade name Halar in the early 1970s. This is essentially a 1 1 alternating copolymer compounded with stabilising additives. The polymer has mechanical properties more like those of nylon than of typical fluoroplastic, with low creep and very good impact strength. Furthermore the polymers have very good chemical resistance and electrical insulation properties and are resistant to burning. They may be injection moulded or formed into fibres. 

In the early 1950s a new class of polyamides became available differing from the nylons in that they contained bulky side groups, had a somewhat irregular structure and were of low molecular weight (2000-5000). They are marketed under such trade names as Versamids and Beckamides . 

As with the aliphatic polyamides such as nylons 6 and 66, the polyphthalamides were developed as plastics materials only after their sucessful use in the field of fibres. Such materials were introduced in 1991 by Amoco under the trade name of Amodel. 

Linear polyesters Polyesters may be obtained in a wide variety of forms including rubbers, fibres, films, laminating resins, surface coatings and thermoplastic moulding powders. The last named are somewhat similar to the nylons but are more rigid. Chemical applications, would appear to be limited because of their sensitivity to alkaline solutions and hot water. 

Camphor, molecular model of, 129 specific rotation of, 296 Cannizzaro, Stanislao, 724 Cannizzaro reaction. 724 mechanism of, 724 Caprolactam, nylon 6 from, 1213 Capsaicin, structure of. 78 -curbahlehyde, aldehyde name ending, 696... 

Condensation polymerization of amines with carboxylic acids leads to the polyamides, substances more commonly known as nylons. A common polyamide is nylon-66, which is a polymer of 1,6-diaminohexane, H2N(GH2)6NH2, and adipic acid, HOOC(CH2)4COOH. The 66 in the name indicates the numbers of carbon atoms in the two monomers. 

The name Nylon was given by the Du Pont company of America to their first synthetic condensation polymer formed by the reaction of difuncfional acids with difuncfional amines, ft had been made as part of the fundamental programme of W. H. Carothers to investigate the whole topic of polymerisation. The term has gradually been extended to other related polymers. These materials are strictly polyamides, but this term includes that otherwise distinct class of natural macromolecules, the proteins. The term nylon is retained for its usefulness in distinguishing synthetic polyamides from the broader class of such polymers. 

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