Wool and Silk

Type Side Group Amino Acid Content (wt %) Wool Silk  

Source Harris, Ni., Handbook of Textile Fibers, Harris Research Laboratories, 1954. 

Due to the laige amount of functional side groups and the C=0 and N-H groups on the polymer main chains, many different types of intermolecular bonds can be formed in wool and silk libers  

Ionic secondary bonds occur between acidic and basic side groups. Aromatic ring association can be formed between the aromatic rings in some of the side groups. 

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The production of polyester fibers leads that of all other types Annual United States production of poly ester fibers is 1 6 million tons versus 1 4 million tons for cotton and 1 0 million tons for nylon Wool and silk trail far behind at 0 04 and 0 01 million tons re spectively... 

Wool and Silk. Wool must be caretiiUy bleached to avoid fiber damage. It is usually bleached with 1—5% hydrogen peroxide solutions at pH 8—9 for several hours at 40—55°C or at pH 5.5—8 for 20—60 min at 70—80°C. Silk is bleached similarly, but at slightly higher temperatures. 

The ancient process of stoving is stiU occasionally used to bleach wool and silk with sulfur dioxide. In this process, wet fabrics are hung in chambers of burning sulfur or sulfur dioxide gas for at least 8 h. The fabrics are then washed with sodium sulfite to remove excess sulfur dioxide. Fabric so treated may have unpleasant odors, and the original color eventually returns, but the process is simple and inexpensive. 

Because it is also a proteia, silk can be dyed as wool, but ia practice the dyes used are generally acid dyes ia view of the fiber not being treated to any severe washing ia its life. The main difference between wool and silk is ia the preparation of the fiber for dyeiag. 

T artrazine, 4,5-dihydro-5 -oxo-1 -(4-sulfophenyl)-4-[(4-sulfophenyl)azo]-1// -pyrazole-3-carboxylic acid trisodium salt was discovered by Ziegler in 1884 and is used as a dye for wool and silk. It is used as a colour additive in foods, drugs and cosmetics, and is an adsorption-elution indicator for chloride estimations in biochemistry (B-76MI40404). 

This is not the case in most fires where some oi the intermediate produces, formed when large, complex molecules are broken up, persist. Examples are hydrogen cyanide from wool and silk, acrolein from vegetable oils, acetic acid from timber or paper, and carbon or carbon monoxide from the incomplete combustion of carbonaceous materials. As the fire develops and becomes hotter, many of these intermediates, which are often toxic, are destroyed—for example, hydrogen cyanide is decomposed at about 538°C (1000°F). 

In addition to the natural protein fibres wool and silk, fibres have been produced commercially from other proteins. These materials were introduced as wool substitutes but today have little or no significance. Mention may, however, be made of ArdiP products from the groundnut protein and marketed for some years after World War II by ICI. Compared with wool it had inferior wet and dry strength and abrasion resistance. The inclusion of up to 20% ArdiP into wool, however, yielded a product with negligible loss in wearing properties. 

Elderberries yield a violet color. In times past, not only were the berries used to color hair and wine, but also to enliven fabric and basket materials. Elder-berries have also been used to make beautifully colored inks and to tint paper blue. With alum used as a mordant to fix the dye, the berries give a purple color, used best on wool and silk. Elderberries mixed with alum and salt produce a lilac hue, and mixed with alum and cream of tartar they make a lovely crimson shade. Chrome used as a mordant with elder-berries produces a blue dye and tin used as a mordant produces blue gray. 

Solubilized vat Cotton, wool, cellulose, and protein fibers silk Impregnated fiber when treated with an oxidized agent usually sulfuric acid and sodium nitrite for cotton dichromate wool and silk therefore, no alkali is involved. This class is applicable to cellulose and protein fibers Dyeing, printing and wool in fast shades... 

Wool and silk are protein-like substances and hence are amphoteric. Accordingly, they can combine with acids as well as with bases. For this reason wool and silk can be dyed directly by dyes in virtue of their auxochromic groups. 

The members of this class dye wool and silk directly, but cotton only when the latter is mordanted by tannin. They are fast neither to acids nor to alkalis for reasons which depend on important alterations in the compounds. If a little dilute hydrochloric acid is added to an aqueous solution of crystal violet the colour changes to green. One N(CH3)2-group takes part in the change and there is formed the salt with two equivalents of acid ... 

Most plant and animal materials contain natural fibers that have been concerted into useful fibers for thousands of years including ropes, building materials, brushes, textiles, and brushes (Table 18.6). Animal protein fibers such as wool and silk are no longer competitive with synthetic fibers with respect to cost but are still often utilized in the production of high-end rugs. Some of these rugs are hundreds of years old yet retaining their color and physical properties. 

Till this time, polymer science was largely empirical, instinctive, and intuitive. Several polymers were commercially available prior to World War I celluloid, shellac, Galalith (casein), Bakelite, and cellulose acetate plastics hevea rubber, cotton, wool, and silk rayon fibers Glyptal polyester coatings bitumen or asphalt, and coumarone-indene and petroleum resins. However, as evidenced by the chronological data shown in Table 1.1, there was little... 

Before 1800 Cotton, flax, wool, and silk fibers bitumens caulking materials glass and hydraulic cements leather and cellulose sheet (paper) natural rubber Hevea brasiliensis), gutta percha, balata, and shellac 1839 Vulcanization of rubber (Charles Goodyear)... 

Some naturally occurring polymers such as cellulose, starch, wool, and silk are classified as condensation polymers, since one can postulate their synthesis from certain hypothetical reactants by the elimination of water. Thus cellulose can he thought of as the polyether formed by the dehydration of glucose. Carothers included such polymers by defining condensation polymers as those in which the formula of the repeating unit lacks certain atoms that are present in the monomer(s) from which it is formed or to which it may be degraded. In this... 

Nylon, Wool and Silk. Because of their common structural features, nylon (generi-caUy polyamide), wool and sUk are normally considered together, especially as they... 

Clothes have long been made of natural fibers such as cotton, wool, and silk. But beginning in the 20th century, textile manufactures have had other options. Nylon was the first synthetic (human-made) fiber, introduced in 1939. Others, such as polyester and spandex, followed. These... 

WOOL AND SILK (FROM SILK WORMS) ARE ANIMAL FIBERS. 

PLACE TEST TUBES IN AND. NOTE RESULT. WOOL AND SILK HAVE DISSOLVED, THE OTHERS NOT. 

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