Polytetrafluoroethylene (PTFE) is a special type of engineering plastic that has good physical and chemical properties and can withstand "aqua regia", commonly known as the "king of plastics". PTFE has a wide temperature range and can be continuously used for a long time between 180-250 ℃. Its friction coefficient is very low, only 0.04, without water absorption and is not flammable. However, due to the non polarity of PTFE molecular chains, the mechanical properties of PTFE are poor. By utilizing the excellent friction and high-temperature performance of PTFE and using other engineering plastics with higher mechanical strength for blending modification, the advantages of each component can be comprehensively blended, achieving complementary advantages, and producing high-performance engineering plastic friction materials, thereby expanding the application field of engineering plastics. There are several commonly used engineering plastics that blend with PTFE:

1 ● Polyoxymethylene (POM)

POM is a highly crystalline linear thermoplastic polymer with unique mechanical properties, excellent oil resistance, chemical resistance, creep resistance, and good thermal and electrical properties. It has low water absorption and can maintain its mechanical, chemical, and electrical properties over a wide temperature range. It is an engineering plastic with excellent comprehensive performance. By using PTFE to modify POM, defects such as poor toughness and low notch impact strength can be improved, resulting in the production of high-performance friction materials.

2 ● Polyether ether ketone (PEEK)

PEEK has excellent comprehensive performance, good heat resistance, long-term use temperature up to 240 ℃, fiber reinforced grade up to 300 ℃, and also has high strength, high rigidity, creep resistance, good fatigue resistance, as well as self flame retardant, oil resistance, organic solvent resistance and other characteristics. Since its inception in the 1960s, PEEK and its composite materials have been widely used in industries such as aviation, aerospace, and electronics. Glass fiber (GF)/carbon fiber (CF) hybrid reinforced PEEK/PTFE composite material is a wear-resistant material with excellent comprehensive performance, which has advantages such as high temperature resistance and wear resistance, and can be used as structural components in high-temperature environments.

3 ● Polyphenylene sulfide (PPS)

PPS is a new type of engineering plastic pioneered by Philips Petroleum Company in 1968. PPS, known as a "new type of plastic for the jet age," has outstanding thermal stability, good adhesion, electrical insulation, corrosion resistance, and self extinguishing properties. Its disadvantage is poor impact resistance and difficulty in forming and processing. The inert surface of PTFE makes it difficult to bond with PPS. Domestic scholars use PPS powder and a mixture to mix and mill before adding PTFE powder to make a coating. PTFE/PPS alloy coating solves the problem of high melt flow rate and difficulty in direct molding of PPS. It can maintain high mechanical properties above 300 ℃ and is mainly used for corrosion-resistant pumps, flanges, gaskets, as well as dynamic seals, shaft sleeves, automotive engine valve covers, chromatograph sliding seals, and guide components.

4 ● Polyamide (PA)

Adding PTFE to PA mainly improves its sliding performance. When the filling amount of PTFE is greater than 10%, the friction and wear resistance of PA is also improved, and its friction coefficient and wear amount are significantly reduced.

5 ● Polyimide (PI)

PI is a general term for polymers containing imide groups in the main chain, and is a representative of heterocyclic polymer compounds first industrialized by Dupont Company in the United States. It has outstanding heat resistance, radiation resistance, and wear resistance. Products made by blending thermoplastic polyimide (TPI) with PTFE or adding other fillers can be used for automotive engine hood components, aerospace equipment, and office electronic equipment.