Organic fibrous materials

This includes organic fibrous materials on a cellulose base such as paper, pressboard, cotton, cotton cloth and natural silk etc., impregnated with lacquers or immersed in an insulating liquid. The impregnation or immersion ensures that the oxygen content of the air does not affect... 

This comprises composite materials on mica, glass fibre and asbestos bases, impregnated or glued together with silicone resins or silicone elastomer. These materials must not contain any organic fibrous materials such as paper or cloth backing, which is covered under class B and even F insulation systems. 

One of the principal objectives of any immersional calorimetric investigation of organic fibrous materials is to assess the thermodynamic functions... 

Fig. 19. High-magnification image of an aligned goethite crystal and stained organic fibrous material running parallel to the crystal growth direction (arrow). Bar = 0.1 /nm.

The primary constituent of practically ah. asbestos—organic friction materials was asbestos fiber, with smah quantities of other fibrous reinforcement material. Asbestos was chosen because of its thermal stabhity, its relatively high friction, and its reinforcing properties. Because asbestos alone did not offer ah of the desked properties, other materials cahed property modifiers were added to provide desked levels of friction, wear, fade, recovery, noise, and rotor compatibihty. A reski bkider held the other materials together. This bkider is not completely neutral and makes contributions to the friction and wear characteristics of the composite. The more commonly used kigredients can be found ki various patents (6—9). 

Organic clutch materials contain continuous-strand reinforcements in addition to fibrous reinforcements. These include cotton (primarily for processing), other organic yams, carbon—graphite yam, and asbestos yam, and brass wire or copper wire for high burst strength. 

Asbestos may be used for improved heat and chemical resistance and silica, mica and china clay for low water absorption grades. Iron-free mica powder is particularly useful where the best possible electrical insulation characteristics are required but because of the poor adhesion of resin to the mica it is usually used in conjunction with a fibrous material such as asbestos. Organic fillers are commonly used in a weight ratio of 1 1 with the resin and mineral fillers in the ratio 1.5 1. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials Attacks rubber and most fibrous materials. May cause ignition of organic materials such as wood. Some acids, such as sulfuric acid, may result in explosion Stability During Transport Stable Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Both inorganic and organic sorbent materials are suitable for apphcation in partition PLC. The relevant material in this connection is cellulose. Celluloses are natural products with the universal chemical formula (CgHioOj),. These native celluloses have a fibrous structure and they need to be groimd and purified before use in PLC. Besides native cellulose, microcrystalline cellulose can also be used in partition PLC. In this case the cellulose has been recrystaUized and is rod-shaped. The specific surface area of celluloses is in the range of about 2 m /g. 

It is possible to build within the formation a porous pack that is a mixture of fibers and the proppant. The fibrous material may be any suitable material (e.g., natural or synthetic organic fibers, glass fibers, ceramic fibers, carbon fibers). 

The nucleus contains bundles of a fibrous material known as chromatin, which is made up of mixed proteins and deoxyribonucleic acid (DNA), the substance that carries the genetic information of the living organism of which the cell is a component. All cells replicate by division. When a cell replicates, DNA in the chromatin of the nucleus passes the genetic information from one generation to the next one. As the cell divides, the chromatin clusters into rodlike structures known as chromo-... 

Dyes, often also called coloring matters or colorants, are intensely colored, soluble organic substances used to impart color to fibrous materials (see Textbox 66). Not all colored and soluble organic substances, however, are dyes only those whose molecules have a considerable structural complexity are useful for imparting color to other materials. Moreover, a substance is considered a dye only if the color it imparts is fairly permanent, that is, resistant to fading and disappearance. 

Mixtures of perchlorate salts with finely divided or fibrous organic materials are likely to be explosive. Porous or fibrous materials exposed to aqueous solutions and then dried are rendered explosively flammable and are easily ignited. 

In Vitro Systems. Different biochemical approaches provide a variety of methods for comparing and evaluating fiber toxicity. Organ cultures, cultured cells, and cells in suspension from humans and animals can be exposed to fibrous materials or, alternatively, cells from treated animals, bacterial cells, and so on can be used. Many hundreds of experiments have been performed, but it is difficult to apply the results, and in many cases extrapolation to humans is not warranted. Nevertheless, cell systems provide excellent data on which to base our understanding of the mechanisms related to fiber-induced disease a few selected examples follow. 

Source Agriculture, industrial processes. Specifically, industrial plants for the production of pulp from timber or other fibrous materials, and paper or board production are responsible of 70% of the total organic carbon released directly into water from industry per year. 

Fluorine Miscellaneous materials, 4304 Magnesium perchlorate Cellulose, etc., 4078 /V-Meth yI morpholine oxide, 1991 Nitric acid Cellulose, 4430 Perchloric acid Cellulose and derivatives, 3992 Perchloric acid Hydrofluoric acid, Structural materials, 3992 Potassium chlorate Cellulose, 4011 Potassium nitrate Cellulose, 4645 Sodium chlorate Paper, etc., or Wood, 4033 Sodium nitrate Fibrous material, 4716 Sodium nitrite Wood, 4715 Sodium peroxide Fibrous materials, 4797 Zinc permanganate Cellulose, 4705 BLEACHING POWDER Wood perchlorates Organic matter See SUGARS... 

---