Insulation, electrical wire

Electrical Properties. CeUular polymers have two important electrical appHcations (22). One takes advantage of the combination of inherent toughness and moisture resistance of polymers along with the decreased dielectric constant and dissipation factor of the foamed state to use ceUular polymers as electrical-wire insulation (97). The other combines the low dissipation factor and the rigidity of plastic foams in the constmction of radar domes. Polyurethane foams have been used as high voltage electrical insulation (213). 

The principal chemical markets for acetylene at present are its uses in the preparation of vinyl chloride, vinyl acetate, and 1,4-butanediol. Polymers from these monomers reach the consumer in the form of surface coatings (paints, films, sheets, or textiles), containers, pipe, electrical wire insulation, adhesives, and many other products which total biUions of kg. The acetylene routes to these monomers were once dominant but have been largely displaced by newer processes based on olefinic starting materials. 

Because of the stringent U.S. requirements on handling lead-based powders, these stabilizers are only found in flexible electrical wire insulation in the United States because no other stabilizers have been developed which have the low conductivity afforded by these materials. 

The major applications of rubbery materials today include automotive tires, rubber bands, tubing of various kinds, electric wire insulation, elastomeric urethane fibers for undergarments, and silicone rubber. Such types of polymers are important materials in our 21st-century world. 

Uses. In synthetic wax in electric wire insulation in lubricants... 

Perfluoroalkyl-l,3,5-triazines are very stable to oxidation and heat. They have potential as lubricating fluids for use in aerospace work (B-74MI22003). Their polymeric products are stable elastomers with excellent rubber-like properties for use as electrical wire insulation and seals for hydraulic, lubricating and fuel systems of aircraft (B-80MI22001). Perfluoro-2,4,6-tri-n-heptyl-l,3,5-triazine is a valuable reference standard for precise mass... 

Chapter 4 60° angle Bunsen burner test for electric wire insulation. The test is also conducted in a cabinet and the flame is applied for 30 s. Manufacturers of commercial aircraft tend to require higher fire performance than that which this test provides, but many of the electrical services incorporated into the aircraft by the airlines use this test. 

Low molecular weight polymeric plasticizer used in electrical wire insulation and coatings for wood, metal, fabrics and paper. 

Use Tire carcasses and linings, especially for tractors and other outsize vehicles electric wire insulation encapsulating compounds steam hose and other mechanical rubber goods pond and reservoir sealant. Latex is used for paper coating, textile and leather finishing, adhesive formulations, air bags, tire vulcanization, self-curing cements, pressure-sensitive adhesives, tire-cord dips, sealants. 

Antioxidants. Certain components of heat stabilizers (polyols, phosphites) also serve as antioxidants. The protection against oxidative attack is not as great in PVC as it is in certain ethylenically unsaturated materials. However, PVC compounds may require protection in the high-temperature service as in electrical wire insulation bisphenol A is often incorporated into the plasticizer for this purpose. Impact modifiers containing unsaturation such as acrylonitrile-butadiene-styrene polymers often require antioxidant protection. Hindered phenols such as butylated hydroxytoluene are often used for this purpose, especially when outdoor applications are involved. 

Table 5.6. Examples of Electric Wire Insulation Molded from Daikin PTFE ° ...

The process of polymer blending was used for improving the mechanical properties of electric wire insulation, as early as 1968 [Ku and Liepins,... 

OTHER COMMENTS used as an inert component of resins for coating or impregnating textiles and for flame and waterproofing wood paper utilized in electric wire insulation and also as additives to special lubricants. 

Hexachloronaphthalene is used in electric wire insulation and as an additive to lubricants. 

Although the exact mechanism of the thermal, heat-induced decomposition of PVC remains unknown, most chemists agree that the chlorine atoms present in the polymer play an important role. Lead salts are added to PVC both to provide anions less reactive than chloride and to provide lead ions to combine with the released chloride ions. As a beneficial side effect, the lead chloride formed gives PVC enhanced electrical resistance, making lead stabilizers particularly useful in producing PVC for electrical wire insulation. 

ELECTRIC WIRE INSULATION/. FROM SYMP. ON THERMAL RADIATION OF SOLIDS, SAN FRANCISCO, CALIF.,... 

There are three broad classifications for rigid PVC compounds Type II, chlorinated polyvinyl chloride (CPVC), and Type I. Type II differs from Type I due to greater impact values, but lower chemical resistance. CPVC has greater high temperature resistance. These materials are considered unplasticized, because they are less flexible than the plasticized formulations. PVC has a broad range of applications from high volume construction related products to simple electric wire insulation and coatings. CAS numbers are 9002-86-2, 8063-94-3, 51248-43-2, and 93050-82-9. 

Uses of Chlorosulfonated Robber. CSM is used in applications similar to those of CM. It is used in automotive hoses, tubes, gaskets, electrical wire insulation (even in high-voltage power stations), industrial hoses, tank Unings, coated fabrics, conveyor belting, and other applications. 

The process of polymer blending was used for improving the mechanical properties of electric wire insulation, as early as 1968 (Ku and Liepins 1987). In 1978, it was found that the use of a HDPE/LDPE blend enhanced the electrical treeing inception voltage (Nitta and Funayama 1978). This approach to electrical treeing inhibition and some of the experimental results on the use of SB/LDPE and HDPE/LDPE blends are given in Table 10.30 (Wu and Chen 1983). 

Synthetic polymeric plastic materials accumulate in the environment at a rate of 25 million metric tonnes per armum. Polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP) and polystyrene (PS) are all used globally in large quantities. In terms of consumption, PVC is the third most important thermoplastic material with widespread applications ranging from packaging to healthcare devices, toys, building materials, electrical wire insulation, clothes and furnishing [2],... 

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