Modified fibres nylon

Research into controlled-release antimicrobials continues with organo-silver compounds and silver zeolites, which are promising candidates for textile finishes. Silver ions, for example, incorporated in glass ceramic, have a very low toxicity profile and excellent heat stability. These principles are also used for fibre modification, an alternative to the antimicrobial finishes with high permanence. In recent years a variety of antimicrobial modified fibres have been developed, including polyester, nylon, polypropylene and acrylic types. An example of these fibre modifications is the incorporation of 0.5-2 % of organic nitro compounds... 

Fibre choices for thermal protective clothing include inherently flame resistant (FR) fibres such as the meta- and para-aramids, polyamide-imide, polybenzimidazole, modacrylic and chemically modified fibres such as viscose and modal, polyester, and nylon, as well as FR treated or finished cotton and wooP"" (see also Chapter 8). The... 

Many brilliantly coloured and tinctorially strong basic dyes for silk and tannin-mordanted cotton were developed in the early decades of the synthetic dye industry. Most of these belonged to the acridine, azine, oxazine, triarylmethane, xanthene and related chemical classes their molecules are usually characterised by one delocalised positive charge. Thus in crystal violet (1.29) the cationic charge is shared between the three equivalent methylated p-amino nitrogen atoms. A few of these traditional basic dyes are still of some interest in the dyeing of acrylic fibres, notably as components of cheap mixture navies and blacks, but many modified basic dyes were introduced from the 1950s onwards for acrylic and modacrylic fibres, as well as for basic-dyeable variants of nylon and polyester [44] ... 

More controlled and efficient fixation is possible when the reactant is applied as a pretreating agent [146]. If nylon given such a pretreatment is subsequently dyed with the conventional chlorotriazine dye Cl Reactive Red 3 (7.2), the substantivity and fixation of the latter are markedly lowered because the anionic XLC residues have reacted with N-terminal amino groups in the fibre. Treatment of the modified nylon with ammonia, however, restores some degree of dyeability. Opposite effects are observed if Cl Reactive Red 3 is reacted with ethylenediamine to form an aminoalkyl derivative (7.131). This nucleophilic dye exhibits a high degree of fixation only on the modified nylon that has been pretreated with XLC. 

In this paper, all the blends and composites are designated by the type of matrix (G for the neat nylon, D for the 8 wt % rubber-modified nylon and N for the 20 wt % rubber-modified nylon), the concentration of fibres and the type of fibre/matrix interface (A or B). As an example, a material designed DlOB is a ternary blend made of DZ matrix and 10 wt% of type B fibres. After drying the specimens for 24 hours at 100°C, they were stored in plastic bags inside a desiccator. In comparison with freshly injection moulded samples, the moisture content in the specimens ready for mechanical testing is about 2 wt%. All the mechanical tests were conducted in an environmental chamber in controlled conditions a temperature of 20°C under a continuous argon flow. 

Table 8.15 Damage to nylon fibres and Frotte reaction with modified zinc chloride-iodine reagent, according to Bubser and Modlich ...

Terylene, like nylon, is thermoplastic and can have permanent pleats or shapes imposed by the action of heat with or without steam. It breaks under loads of 4-2 to 4-8 g per denier and the continuous filament has an extension of 22 to 30 per cent at the breaking point. The fibre has marked crystallinity as shown by the X-ray diffraction diagram illustrated in Fig. 2.7, and by the low moisture regain of 0-4 per cent. The closely packed and highly-orientated molecules make Terylene markedly hydrophobic and difficult to dye. Modified polyester fibres are produced with an affinity for both disperse and cationic dyes. 

Acid dyes Reactive dyes Basic Direct dyes Mordant dyes Disperse dyes Vat dyes Solvent dyes Fluorescent brightners Other dye classes Nylon, sUk, wool, paper, inks and leather Cotton, wool, sUk and nylon Paper, polyacrylonitrile, modified nylon, polyester and inks Cotton, rayon, paper, leather and nylon Wool, leather and anodised altiminirun Polyester, polyamide, acetate, acrylic and plastics Cotton, rayon and wool Plastics, gasoline, varnishes, lacquers, stains, inks, fats, oils and waxes Soaps and detergents, aU fibres, oils, paints and plastics Food, drugs and cosmetics, electrography, direct and thermal transfer printing... 

Covalent attachment to modified nylon fibres with glutaraldehyde... 

Exhaustive testing in hot antifreeze under pressure established glass fibre reinforced nylon 66 as the best material for the end tanks. Twenty years and many millions of tanks later, it has not been necessary to modify this conclusion, beyond minor formulation changes to improve hydrolysis resistance (see Fig. 6.3). Some French and Italian models used radiator tanks in mPPO at first, because of the dimensional advantages conferred by a low-shrinkage amorphous material, but in the long term the fatigue resistance proved to be inferior to reinforced nylon. 

Comments GF = glass fibres, TZ = impact modified, E = elastomer addition, GFK = glass fibres/beads. Data for material in dry condition, nylon absorbs moisture which alters mechanical and physical properties. ... 

---