1、 Overview of polyimide
Polyimide is an aromatic heterocyclic polymer compound with imide group chain in molecular structure, English name Polyimide (PI for short), which is one of the best varieties of heat resistance in engineering plastics at present. PI, as a special engineering material, has been widely used in fields such as aviation, aerospace, microelectronics, nanomaterials, liquid crystals, separation membranes, lasers, etc.
Recently, countries have included the research, development, and utilization of PI as one of the most promising engineering plastics in the 21st century. Polyimide, because of its outstanding characteristics in performance and synthesis, whether as a structural material or as a functional material, its huge application prospect has been fully recognized. It is known as a "problem solver", and it is believed that "without polyimide, today's microelectronic technology would not exist".

2、 Development history of polyimide
Eric School: Polyimide film (PI) you don't know
3、 Synthesis method
Polyimide is an aromatic heterocyclic macromolecule compound with imide group chain in molecular structure, English name Polyimide (PI for short), which can be divided into homobenzene type PI,
Soluble PI, polyamide imide (PAI) and polyetherimide (PEI).
According to the synthesis method, it can be divided into condensation type and addition type:
1. Polycondensation polyimide: The polycondensation polyimide has been less used as the matrix resin of composite materials, mainly used to manufacture polyimide films and coatings.

Eric School: Polyimide film (PI) you don't know
4、 What are the characteristics of polyimide film?
As a military defense material, polyimide has six characteristics:
1. High temperature resistance: It can withstand high temperatures of over 400 ℃, with a long-term use temperature range of -200~300 ℃, and no obvious melting point.
2. High insulation performance: The dielectric constant is 4.0 at 103 Hz, and the dielectric loss is only 0.004-0.007, belonging to the F to H class insulation material.
3. Excellent mechanical properties: The tensile strength of unfilled plastics is above 100Mpa.
4. Self extinguishing property: polyimide is a self extinguishing polymer with low smoke generation rate.
5. Non toxic: Polyimide is non-toxic and can withstand thousands of times of disinfection.
6. Stability: some polyimides are insoluble in organic solvents and stable to dilute acids. Ordinary polyimides are not resistant to hydrolysis.

5、 Position of Polyimide Film in Plastic Family
Eric School: Polyimide film (PI) you don't know
This picture is a description of the material pyramid of a foreign company. It can be seen from the figure that polyimide (PI) is the top of the material pyramid in terms of heat resistance, chemical resistance and mechanical strength.
6、 Major manufacturer of polyimide film
So far, there are more than 20 varieties of polyimides. With the expansion of its application scope, there will be more and more varieties of polyimides.
7、 Application of polyimide film
Due to the characteristics of polyimide film in performance and synthetic chemistry, it is difficult to find such a wide range of applications of polyimide among many polymers, and it shows outstanding performance in every aspect.

Polyimide film for solar substrate

Polyimide film used as insulating paint in electromagnetic field