Insulating materials are absolutely non-conductive materials?

Release time:

2019-10-28 09:32

no.

Insulating materials are materials used to isolate conductive parts with different potentials. Its conductivity is about 10-10 s/m or less. The insulating materials described in this article are electrical insulating materials. According to the national standard GB2900.5, the definition of insulating materials is: "materials used to electrically insulate devices." That is, materials that can prevent current from passing through. Its resistivity is very high, usually in the range of 10^9 to 10^22Ω·m. For example, in a motor, the insulating material around the conductor isolates the turns and isolates them from the grounded stator core to ensure the safe operation of the motor.

Types of insulating materials: can be divided into three categories: gas, liquid, and solid. Commonly used gas insulating materials include air, nitrogen, sulfur hexafluoride insulating PC film, etc.

Liquid insulating materials mainly include two categories: mineral insulating oil and synthetic insulating oil (silicone oil, dodecylbenzene, polyisobutylene, isopropyl biphenyl, diarylethane, etc.).

Solid insulating materials can be divided into organic and inorganic categories. Organic solid insulating materials include insulating varnish, insulating glue, insulating paper, insulating fiber products, plastics, rubber, varnished cloth and varnished tubes, insulating impregnated fiber products, electrical films, composite products and adhesive tapes, electrical laminated products, etc. Inorganic solid insulating materials mainly include mica, glass, ceramics and their products. In comparison, solid insulating materials are diverse and the most important.

The macroscopic properties of insulating materials, such as electrical properties, thermal properties, mechanical properties, chemical resistance, climate change resistance, and corrosion resistance, are closely related to their chemical composition, molecular structure, etc.

Inorganic solid insulating materials are mainly composed of silicon, boron and various metal oxides, with an ionic structure as the main feature. Their main characteristics are high heat resistance, working temperature generally greater than 180°C, good stability, good resistance to atmospheric aging, chemical resistance and long-term aging performance under electric field; but they are highly brittle, have low impact strength, high pressure resistance and low tensile strength; and poor processability.

Organic materials are generally polymers with an average molecular weight between 104 and 106, and their heat resistance is usually lower than that of inorganic materials. Materials containing aromatic rings, heterocyclic rings, and elements such as silicon, titanium, and fluorine have higher heat resistance than general linear polymer materials.

Therefore, insulating materials do not refer to materials that are absolutely non-conductive, but materials that can act as insulators under certain conditions.

Insulating materials are absolutely non-conductive materials?

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