Modifications And Uses of Polyetheretherketone PEEK

Application areas of PEEK

PEEK is widely used in electrical and electronic, mechanical, aerospace, automotive and other fields.

(1) Electrical and electronic

PEEK is mainly used for wire covering, magnetic conductor covering, high temperature lugs, motor insulating materials, integrated circuit wafer support, etc.: ① wire covering; ② magnetic conductor covering; ③ high temperature lugs; ④ motor insulating materials; ⑤ integrated circuit wafer support.

(2) Machinery

Used as various gears, bearings and joints, piston rings, centrifugal separator parts, detection sensor parts, conveyor chains, cleaning fixtures, etc.

(3) Aerospace

Parts used in aircraft, for example, aircraft radar parts and radomes made of PEEK, excellent weather resistance; made of engine parts, can be used for a long time at 200 ℃ or more. Carbon fiber or glass fiber reinforced PEEK can be used to manufacture aircraft and airship door handles, cabin panels, joysticks and helicopter tail.

British ICI company to PEEK as the main raw material for the manufacture of APC-2 composite materials, than the general-purpose epoxy resin composite material toughness is more than 10 times higher than the cosmic space station, aircraft wings and other large components and other products to replace the epoxy resin. The company to glass fiber reinforced PEEK as raw materials, injection molding method into a rocket igniter tube, instead of the previous metal materials, not only reduces the cost, and is suitable for intense ignition lift-off environment.

(4)Medical equipment

PEEK has the advantages of non-toxic, lightweight, corrosion resistance, etc., excellent biocompatibility, is a very potential biological prosthesis materials. At present, the main application areas of polyether ether ketone in bone defect repair and reconstruction are polyether ether ketone intervertebral fusion device, polyether ether ketone artificial bone joints (artificial hip joints, artificial knee joints, etc.), cranial defect repair, jawbone defect repair, spine/lumbar spine repair, oral repair and other bone defect repair. With the continuous research on this type of material, various PEEK composites have been successfully developed and applied to oral implants, prosthetics, orthodontics and oral and maxillofacial surgery and other fields.

In addition, polyether ether ketone can withstand 3000 cycles of autoclaving at 134 ℃, this feature can meet the high sterilization requirements, the need for repeated use of surgical and dental equipment manufacturing, coupled with its creep resistance and hydrolysis resistance, can be manufactured to require high-temperature steam sterilization of various medical devices.

(5) Energy field

PEEK can meet the high-performance requirements of nuclear industry components. Radiation resistance is one of the key performance of the nuclear power industry application materials, ordinary thermoplastic materials subject to electromagnetic or particle-type ionizing radiation may become brittle. Because PEEK has an energy-stable chemical structure, parts made with PEEK materials can still work normally after being exposed to high doses of ionizing radiation. Radiation resistance, excellent electrical properties at high temperatures, outstanding mechanical strength, good chemical resistance, very low moisture absorption and excellent resistance to hydrolysis make it an ideal choice for high-performance parts and components in the nuclear power industry.

In addition, PEEK is also specialized in high temperature and high pressure and chemical corrosive environment, can expand the scope of oil and gas exploration, can be used to manufacture large-scale petrochemical production line of hydrogen tighteners and petroleum gas tighteners, such as ring, mesh valve sheet.

(6) Other fields

At present, PEEK new materials have been successfully applied in the field of beverage canning machinery, typical uses include: aseptic canning production line used in the high life requirements of PEEK wear-resistant forks, bushings and plates, etc.; food and beverage processing machinery components such as ovens, freezers, deep fryers, ultra-filtration membranes, canning machines, etc.; injection molded into the wear-resistant bushings, housings, bearings, and gaskets in the food and beverage machinery; beer Bottle inspection machine guide roller on the line, and PEEK coatings made of high-temperature wear-resistant braided belt for the conveyor system.

PEEK resin can also be used for the manufacture of special coatings, PEEK fine powder coating on the metal surface, you can get a good insulation, corrosion resistance, heat and water resistant metal PEEK coated products, which are widely used in chemical corrosion, household appliances, electronics, machinery and other fields. In addition to emulsion spraying, powder electrostatic spraying process and flame spraying process can also be used.

Modified and new PEEK

The most important modifications of PEEK are the glass fiber reinforced and carbon fiber reinforced grades. glass fiber or carbon fiber reinforced PEEK significantly improves its mechanical strength, modulus, and heat resistance, which have already been discussed in the previous section (see Table 1-1). New grades of PEEK and PEEK alloys that have been developed in recent years are described below.

1. Conductive PEEK

In recent years, for the semiconductor, liquid crystal display glass substrates and integrated circuits wafer holder and other manufacturing engineering materials, not only requires high toughness, dimensional stability and lightweight features, but also requires high-temperature treatment of anti-static properties, for this reason, Japan's Mitsui Toho Chemical Co. developed a successful new grade of conductive PEEK KNE5010, which not only will be the PEEK surface resistivity from 1016Ω down to 108Ω. It not only reduces the surface resistivity of PEEK from 1016Ω to 108~1010Ω, but also maintains a series of excellent properties of PEEK (Table 4-1).

Table 4-1 Properties of PEEK conductive grades

2. High Strength PEEK

In 1994, Japan's Mitsui East Pressure Chemical Company developed a new grade of high-strength PEEK PKU-CF30, which is a mixture of PEEK and specially treated carbon fibers reinforced by the production of new materials, with excellent mechanical strength and modulus (Table 4-2). The tensile strength is as high as 284 MPa, which is only slightly lower than that of aluminum alloys, while the specific strength is as high as 206 MPa, which is much higher than that of aluminum alloys.

PKU-CF30 as raw material, through the injection molding of automobile turbine loading impeller, than the use of aluminum alloy manufacturing quality can be reduced by half, and products of high strength, heat resistance and fatigue resistance is also very good, is an excellent performance and affordable injection products, is now used in Nissan automobile's main turbine car.

Table 4-2 Comparison of properties of high-strength PEEK PKU-CF30 with other materials

3. PEEK alloy

PEEK resin is expensive, and as a heat-resistant polymer, its glass transition temperature (143~) is slightly low. When exceeding the glass transition temperature, its strength and modulus rapidly decline, usually using glass fiber reinforced or alloying methods to improve.PEEK can be blended with PSF, PEI (polyetherimide), PES and other non-crystalline high glass transition temperature of the resin, made of alloys with a high glass transition temperature. For example, PEEK and PEI according to 50/50 (mass ratio) blended polymer alloys, glass transition temperature of 180 ℃, 37 ℃ higher than PEEK. At this time, the absolute crystallinity and crystallization rate of PEEK is reduced, but the crystallization has not disappeared. For PEI, the addition of PEEK can improve its solvent resistance.

PEEK and PPS blending, not only to improve the fluidity of the PEEK melt, improve the glass transition temperature, but also to reduce costs.

Polyaryletherketones of different varieties can also be mixed with each other to form polymer alloys, such as PEEK and PEK, etc., according to their molecular structure of the ether, ketone ratio, through the blending to adjust the melting point and glass transition temperature.PEEK and LCP (Liquid Crystal Polymers) polymer alloys can significantly inhibit the reduction in strength and modulus in the glass transition temperature of the PEEK above. PEEK/LCP alloys have increased helix flow lengths and improved molding properties compared to PEEK.