POLYESTER FIBRE

HOCHj CHjOH. Colourless, odourless, rather viscous hygroscopic liquid having a sweet taste, b.p. 197 C. Manufactured from ethylene chlorohydrin and NaHC03 solution, or by the hydration of ethylene oxide with dilute sulphuric acid or water under pressure at 195°C. Used in anti-freezes and coolants for engines (50 %) and in manufacture of polyester fibres (e.g. Terylene) and in the manufacture of various esters used as plasticizers. U.S. production 1979 1 900 000 tonnes. 

Polyesters from diols and dicarboxylic acids (polyester fibres). 

PETUKHOV, b. v The Technology of Polyester Fibres, Pergamon, Oxford (1963)... 

HPLC-UV is a popular technique to analyse textile dyes extracted from polyester fibres [697], acidic dyes from wool fibres [698] and basic dyes from acrylic fibres [699]. HPLC provides better sensitivity and resolution than TLC [697-699]. GE-RPLC has been used for the determination of 18 disperse dyes (e.g. Navy D-2G-133, Orange CB, Yellow D-3R and Red D-2G) extracted from polyester [700]. Compared with the traditional TLC method, HPLC offers lower detection limits, better observation of contaminant peaks, and reproducible quantitative results. HPLC has also been used to determine azo dyes [701,702]. 

The traditional use of dyes is in the coloration of textiles, a topic covered in considerable depth in Chapters 7 and 8. Dyes are almost invariably applied to the textile materials from an aqueous medium, so that they are generally required to dissolve in water. Frequently, as is the case for example with acid dyes, direct dyes, cationic dyes and reactive dyes, they dissolve completely and very readily in water. This is not true, however, of every application class of textile dye. Disperse dyes for polyester fibres, for example, are only sparingly soluble in water and are applied as a fine aqueous dispersion. Vat dyes, an important application class of dyes for cellulosic fibres, are completely insoluble materials but they are converted by a chemical reduction process into a water-soluble form that may then be applied to the fibre. There is also a wide range of non-textile applications of dyes, many of which have emerged in recent years as a result of developments in the electronic and reprographic... 

There is a wide diversity of chemical structures of anthraquinone colorants. Many anthraquinone dyes are found in nature, perhaps the best known being alizarin, 1,2-dihydroxyanthraquinone, the principal constituent of madder (see Chapter 1). These natural anthraquinone dyes are no longer of significant commercial importance. Many of the current commercial range of synthetic anthraquinone dyes are simply substituted derivatives of the anthraquinone system. For example, a number of the most important red and blue disperse dyes for application to polyester fibres are simple non-ionic anthraquinone molecules, containing substituents such as amino, hydroxy and methoxy, and a number of sul-fonated derivatives are commonly used as acid dyes for wool. 

Polyamide and polyester fibres are generally scoured using an alkyl poly(oxyethylene) sulphate and sodium carbonate. Some polyester qualities are subjected to a causticisation treatment with sodium hydroxide in the presence of a cationic surfactant to give a lighter fabric with a silkier handle [154,156]. This treatment involves etching (localised saponification) of the polyester surface and is broadly analogous to the S-finish used on triacetate fibres. The process has attracted considerable interest in recent years but its... 

The polyester sizes used have a much lower average molecular mass than polyester fibres. These structures (10.69) contain sulphonic acid groups and may be water-soluble or water-dispersible types. The degree of sulphonation is low [171]. If these resins are subjected to a high pH, the sulphonate groups can be hydrolysed, giving an insoluble resin that is very difficult to remove from the fibres. 

Figure 10.67 indicates the probable distribution of a silicone containing the optimum content of aminoethyliminopropyl groups when applied to a polyester fibre surface. In this case the attachment is through hydrophobic polymer-fibre interaction and the mobility of the silicone chain segments is increased by electrostatic repulsion between neighbouring cationic groups. Dependence of softness of the treated polyester fabric on the proportion of... 

Essentially nonionic soil-release agents comprise polyesters, polyamides, polyurethanes, polyepoxides and polyacetals. These have been used mainly on polyester and polyester/ cellulosic fabrics, either crosslinked to effect insolubilisation (if necessary) or by surface adsorption at relatively low temperature. Polyester soil-release finishes have been most important, particularly for polyester fibres and their blends with cellulosic fibres. These finishes, however, have much lower relative molecular mass (1000 to 100 000) than polyester fibres and hence contain a greater proportion of hydrophilic hydroxy groups. They have been particularly useful for application in laundering processes. These essentially nonionic polymers may be given anionic character by copolymerising with, for example, the carboxylated polymers mentioned earlier these hybrid types are generally applied with durable press finishes. 

The trade name of a polyester fibre used as textile reinforcement for mbber in products such as tyres, belting and hose. It is a truly synthetic fibre made from polyethylene terephthalate, a condensation product of terephthalic acid and ethylene glycol. 

The discovery in 1979 of the benzodifuranone chromogen (1.14) and its exploitation in red disperse dyes for polyester fibres [23,24] emerged from ICI research towards new chromogens of high colour value, brightness and substantivity to overcome the relative weakness of anthraquinones and dullness of monoazo alternatives in the red disperse dye area. A striking improvement in build-up properties was found by introducing asymmetry... 

Vat dyes are used to colour both components in pale depths on polyester/cellulosic fibre blends [44] but coloration of the polyester component in this case is more closely analogous to disperse dyeing (section 1.6.5). Anthraquinone disperse dyes resemble those vat dyes that are substituted anthraquinone derivatives and in both instances it is exclusively the virtually water-insoluble keto form that is absorbed by the polyester fibre. 

These are the only ranges of precursor products in the Colour Index that are still commercially significant. Azoic dyes have a close formal relationship to those monoazo pigments derived from BON acid or from acetoacetanilides (section 2.3.1) and some are chemically identical with them, although they are used in a totally different way. Azoic components are applied to produce insoluble azo dyes within the textile substrate, which is almost always cotton. Corresponding azoic components for the dyeing of cellulose acetate, triacetate and polyester fibres were once commercially important, but are now obsolete because of environmental hazards and the time-consuming application procedure. 

An aqueous dispersion of a disperse dye contains an equilibrium distribution of solid dye particles of various sizes. Dyeing takes place from a saturated solution, which is maintained in this state by the presence of undissolved particles of dye. As dyeing proceeds, the smallest insoluble particles dissolve at a rate appropriate to maintain this saturated solution. Only the smallest moieties present, single molecules and dimers, are capable of becoming absorbed by cellulose acetate or polyester fibres. A recent study of three representative Cl Disperse dyes, namely the nitrodiphenylamine Yellow 42 (3.49), the monoazo Red 118 (3.50) and the anthraquinone Violet 26 (3.51), demonstrated that aggregation of dye molecules dissolved in aqueous surfactant solutions does not proceed beyond dimerisation. The proportion present as dimers reached a maximum at a surfactant dye molar ratio of 2 5 for all three dyes, implying the formation of mixed dye-surfactant micelles [52]. 

Quite small variations in disperse dye structure can markedly modify substantivity for polyester [89]. This is evident from Figure 3.4, where the two blue dye structures differ only in the 3-acylamino substituent of the diethylaniline coupling component. Replacing acetylamino by propionylamino in dye 3.74 increases the colour yield by at least 30% for a 1.5% depth applied to polyester fibre for 45 minutes at 130 °C. An even more striking example is provided in Figure 3.5, illustrating two isomeric greenish blue dyes applied to... 

In UK, in 1941, Whinfield and Dickson discovered the polyester fibre called terylene chemically it is polyethylene terephthalate. Teryene polymer can be melt spun into a fibre which is widely used in textile industry. 

Figure 8.7 First stage of the stepped isothermal method (SIM) for oriented polyester fibres. Creep strain is measured under a single load while the temperature is increased...

Time to rupture can be predicted by using the accelerated times generated by the creep data, and the creep-rupture characteristic generated by performing twelve of these tests over a range of loads. Conventional long-term creep strain and creep-rupture tests have so far confirmed the validity of the predictions for polyester fibres. Comments on the method have been published by Greenwood and Voskamp [10]. 

Figure 9.1 Schematic prediction of creep modulus of polyester fibres from time-temperature shifted data (based on information from [5])...

Xylene Solvent, dyes, insecticides, polyester fibres, adhesives, wallpaper, varnish, carpeting, wet-process photocopying, pressed-wood products, gypsum board, water-based adhesives, grease solvents, paints, carpet adhesives. 2.9 3... 

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