Cellulosic fibers, insulation material

Sachinvala, N. D., et al., Use of Sucrose-based Epoxy Formulations and Cellulosic Fibers in the Design, Preparation and Screening of New Composite Insulation Materials, Polymers for Advanced Technologies, 13, 66-79 (2002). 

Much less ordered than PAN-based high-strength CFs are the isotropic CFs. They are produced by the carbonization of isotropic pitch fibers (or other fibrous precursors such as phenolic resins or cellulose, including rayon), without any attempt to obtain a preferred orientation of the polyaromatic molecules in the fiber direction. Consequently, they have a random nanotexture and belong to the low modulus class of CFs [16]. Rather than being used for high-performance reinforcement purposes, they find their application as thermal insulators for furnaces or as reinforcements for cement [1]. Another important use of isotropic CFs is as a feedstock for the production of activated carbon fibers, a material dealt with in Section 2.4.4. 

SE Dortdd. [Lydtdl] Cellulose fiber/ polymer sheet material fiber board used as elec, barrier insulation and low-cost structural material... 

For providing electrical paper sheets [reduce the dielectric loss and increase the dielectric properties), literature attempts include the modification of paper substrate by oxidation [35], impregnation of cellulose paper with insulating oils [36], and replacing the cellulose fibers by some synthetic materials that exhibit better dielectric properties than cellulose, e.g., polypropylene fibers and other synthetic fibers [37, 38], or by treating with ferric chloride [39]. 

Ceramic paper with a high content of a-BN fibers and with microfibrillated fibers as binders (or, for some applications, with cellulose binders [7]) may be used as insulation material in lithium thermal batteries [8]. 

Substances of organic origin, such as wood flour, used for consumption products and in the production of electrical insulation cellulosic fibers (textiles, paper fibers and particles) used mainly to increase impact resistance fruit shell flour, which increases the fluidity of plastic materials under pressing and enhances the dielectric properties and appearance of final products protein flour—casein and soya flours for example—used with carbamides. 

Natural fibers of mineral origin are mainly used for industrial insulation purposes, whereas animal fibers are used for domestic insulation, clothing and carpets. The most beneficial fibers from the environmental point of view are those of vegetable origin. Natural fibers can be considered cellulose fibrils reinforced materials, which consist of microfibrils in an amorphous matrix of lignin and hemicellulose [28]. The cell wall in a fiber is not a homogenous membrane (Figure 4.1). 

In Europe (Denmark and Germany), c. is being tested as a RR, especially for energy production and as an alternative source of pulp for -> paper production. There are also possibilities to use c. as a source of fibers (- cellulose fibers), which might be used for the manufacture of fleeces, insulation material and as a reinforcement of plastics and gypsum. Thus it represents a substitute for wood. 

Thermal insulators comprise an equally broad range of materials. Such inorganics as mineral fibers, magnesia, aluminum silicate, cellulose, and glass fibers are widely used for steam and hot-water pipes, furnaces, and blown-in home insulation. Organic products that are effective include plastic foams (polyurethane, polyvinyl chloride, polystyrene) and cellular rubber. There are a number of materials that may be called double insulators, since they have both electrical and thermal insulating properties,... 

Polycarbonates possess low water absorption, moderately good thermal stability, good electrical insulation properties, exceptionally good dimensional stability, and excellent impact strength. Therefore they are used primarily for dimensionally stable injection-molded articles and for insulating films. However, polycarbonates are susceptible to stress crazing. Polycarbonates are also used as fibers in combination with cellulose for easy boilwashing materials. 

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