What are polyimide materials and what are their specific application?

What are Polyimide materials and what are their specific application?

1, polyimide (Polyimide, sometimes abbreviated as PI), is one of the best overall performance of organic polymer materials. Its high temperature resistance of 400 ° C or more, long-term use temperature range -200 ~ 300 ° C, part of no obvious melting point, high insulation performance, 103 Hz under the dielectric constant 4.0, dielectric loss of only 0.004 ~ 0.007, is F to H level insulation.

2.Polyimide is a class of polymer containing imide ring (-CO-N-CO-) on the main chain, among which the polymer containing phthalimide structure is the most important. As a special engineering material, polyimide has been widely used in aviation, aerospace, microelectronics, nano, liquid crystal, separation film, laser and other fields. In the 1960s, countries are in the research, development and use of polyimide in the 21st century, one of the most promising engineering plastics.

3.Application
(1) Film: It is one of the earliest commodities of polyimide, which is used for slot insulation of motor and cable winding material. The main products are DuPont Kapton, Upilex series of Ube Xing and Zhong Yuan Apical. transparent polyimide film can be used as a soft solar cell base plate.
(2) Coatings: Used as insulating varnish for electromagnetic wires, or as high temperature resistant coatings.
(3) Advanced composite materials: Used for aerospace, aircraft and rocket parts. It is one of the most high temperature resistant structural materials. For example, the U.S. supersonic airliner program designed for speeds of 2, 4M, the surface temperature of 177 ℃ during flight, requiring a service life of 60,000h, it is reported to have identified 50% of the structural materials for thermoplastic polyimide as the matrix resin of carbon fiber reinforced composite materials, the amount of each aircraft is about 30t.
(4) fiber: elastic modulus second only to carbon fiber, as a high-temperature medium and radioactive material filtering materials and bulletproof, fire-resistant fabrics.
(5) foam: used as high temperature Insulation Materials.
(6) engineering plastics: thermosetting and thermoplastic, thermoplastic can be molded or injection molding or transfer molding. Mainly used for self-lubrication, sealing, insulation and structural materials. Guangcheng polyimide material has begun to be used in compressor rotor, piston ring and special pump seal and other mechanical parts.
(7) Adhesive: Used as high temperature structural adhesive. Guangcheng polyimide adhesive has been produced as high insulation potting material for electronic components.
(8) separation membrane: used for the separation of various gas pairs, such as hydrogen/nitrogen, nitrogen/oxygen, carbon dioxide/nitrogen or methane, etc., to remove water from air hydrocarbon raw gas and alcohols. It can also be used as permeate evaporation membrane and ultrafiltration membrane. Because of the polyimide heat and organic solvent resistance performance, in the separation of organic gases and liquids has a particularly important significance.
(9) Photoresist: There are negative and positive adhesive, and the resolution can reach submicron level. With pigment or dye can be used for color filter film, which can greatly simplify the processing process.
(10) Application in microelectronic devices: used as a dielectric layer for interlayer insulation, as a buffer layer can reduce stress and improve yield. As a protective layer can reduce the impact of the environment on the device, but also a-particle shielding effect, reduce or eliminate the soft error of the device (softerror).
(11) Orientation alignment agent for liquid crystal display: Polyimide occupies a very important position in the orientation agent material for TN-LCD, STN-LCD, TFT-LCD and the future ferroelectric liquid crystal display.
(12) Electric-optical materials: used as passive or active waveguide materials optical switch materials, etc. Polyimide containing fluorine is transparent in the communication wavelength range, and the stability of the material can be improved by using polyimide as the base of chromophores.
(13) moisture-sensitive materials: the use of its principle of moisture absorption linear expansion can be used to make humidity sensors