Application progress of special engineering plastics polyether ether ketone (PEEK)

Polyether ether ketone (PEEK) was first developed by Imperial Chemical (ICI) in 1977 and officially sold as VICTREX®PEEK in 1982. In 1993, VICTREX acquired ICI production plant and became an independent company. Weigas has the widest range of poly (ether ketone) products on the market, with a current capacity of 4,250T/year. In addition, the third VICTREX® poly (ether ketone) plant with an annual capacity of 2900T will be launched in early 2015, with a capacity of over 7000 T/a.

Ⅰ. Introduction to performance

PEEK as the most important product of poly (aryl ether ketone, its special molecular structure gives the polymer high temperature resistance, good mechanical performance, self lubrication, easy processing, chemical corrosion resistance, flame retardant, stripping resistance, radiation resistance, insulation stability, hydrolysis resistance and easy processing, such as the excellent performance, is now recognized as the best thermoplastic engineering plastics.

1 High temperature resistance

VICTREX PEEK polymers and blends typically have a glass transition temperature of 143 ° C, a melting point of 343 ° C, a thermal denaturation temperature of up to 335 ° C (ISO75Af, carbon fiber filled), and a continuous service temperature of 260 ° C (UL746B, no fill).

2. Wear resistance

VICTREX PEEK polymer materials provide excellent friction and wear resistance, especially in the wear-resistant modified friction grade grades, over a wide range of pressures, speeds, temperatures and contact surface roughness.

3. Chemical resistance

VICTREX PEEK is similar to nickel steel, providing excellent corrosion resistance in most chemical environments, even at high temperatures.

4. Fire light smoke and non-toxic

VICTREX PEEK polymer material is very stable, 1.5mm sample, ul94-V0 grade without flame retardant. The composition and inherent purity of this material enable it to produce very little smoke and gas in the event of a fire.

5. Hydrolysis resistance

VICTREX PEEK polymers and blends are resistant to chemical attack by water or high pressure steam. Parts made of this material can maintain high levels of mechanical properties when used continuously in water at high temperatures and pressures.

6. Excellent electrical properties

VICTREX PEEK provides excellent electrical performance over a wide range of frequencies and temperatures.

In addition, VICTREX PEEK polymer material also has high purity, environmental protection, easy processing and other characteristics.

Ⅱ. Research on production status

Since the successful development of PEEK, with its own excellent performance, it has been widely favored by people and quickly become a new research focus. A series of chemical and physical modification and enhancement of PEEK has further expanded the application field of PEEK.

1. Chemical modification

Chemical modification is to change the molecular structure and regularity of the polymer by introducing special functional groups or small molecules, such as: changing the proportion of ether ketone groups on the main chain or introducing other groups, branching crosslinking, side chain groups, block copolymerization and random copolymerization on the main chain to change its thermal properties.

VICTREX®HT™ and VICTREX®ST™ are PEK and PEKEKK, respectively. The E/K ratio of VICTREX®HT™ and VICTREX®ST™ is used to improve the high temperature resistance of the polymer.

2. Physical modification

Compared with chemical modification, physical modification is more widely used in practice, including filling enhancement, blending modification and surface modification.

1) Padding enhancement

The most common filling reinforcement is fiber reinforcement, including glass fiber, carbon fiber reinforcement and Arlene fiber reinforcement. Experimental results show that glass fiber, carbon fiber and aramid fiber have a good affinity with PEEK, so they are often selected as filler to enhance PEEK, make high-performance composite materials, and improve the strength and service temperature of PEEK resin. Hmf-grades is a new carbon fiber filled composite from VICTREX that offers superior fatigue resistance, machinability and excellent mechanical properties compared to the current high strength carbon fiber filled VICTREX PEEK series.

In order to reduce friction and wear, PTFE, graphite and other small particles are often added to improve reinforcement. Wear Grades are specially modified and reinforced by VICTREX for use in high-wear environments such as bearings.

2) Blending modification

PEEK blends with organic polymer materials with high glass transition temperature, which can not only improve the thermal properties of composites and reduce the production cost, but also have a great influence on the mechanical properties.

VICTREX®MAX-Series™ is a blend of VICTREX PEEK polymer material and authentic EXTEM®UH thermoplastic polyimide (TPI) resin based on SABIC Innovative Plastics. High-performance MAX Series™ polymer materials with excellent heat resistance are designed to meet the growing demand for more high-temperature resistant PEEK polymer materials.

The VICTREX® T Series is a patented blend based on VICTREX PEEK polymer material and Celazole® polybenzimidazole (PBI). It can be fused and can meet the required excellent strength, wear resistance, hardness, creep and thermal properties under the most demanding high temperature conditions.

3) Surface modification

VICTREX's research, conducted in collaboration with Wacker, a leading producer of liquid silicone, demonstrated that the VICTREX PEEK polymer combines the strengths of both rigid and flexible silicone with the adhesive properties of other engineered plastics. PEEK component as insert, coated with liquid silicone rubber, or double component injection molding technology, can obtain excellent adhesion. The VICTREX PEEK injection mold temperature is 180 ° C. Its latent heat enables rapid curing of silicone rubber, thus reducing the overall injection cycle. This is the advantage of the two-component injection molding technology.

3. The other

1) VICOTE™ coatings

VICTREX has introduced a PEEK based coating, VICOTE™, to address the performance gaps in many of today's coating technologies. VICOTE™ coatings offer high temperature, wear resistance, strength, durability and scratch resistance as well as a wide range of high performance benefits for applications that are exposed to extreme conditions such as high temperature, chemical corrosion and wear, whether in industrial, automotive, food processing, semiconductor, electronics or pharmaceutical parts. VICOTE™ coatings provide extended service life, improved performance and functionality, reduced overall system cost, and enhanced design freedom to achieve product differentiation.

2) APTIV™ films

APTIV™ films offer a unique combination of properties and features inherent in VICTREX PEEK polymers, making them one of the most versatile high-performance film products available. The new APTIV films are versatile and suitable for a variety of applications, including vibration films for mobile phone speakers and consumer speakers, wire and cable insulation and winding jackets, pressure converters and sensor diaphragms, wear resistant surfaces for industrial and electronic products, electrical substrates and aviation insulation felt.

Ⅲ, Application field

PEEK has been widely used in aerospace, automotive, electronics, energy, industrial, semiconductor and medical fields since its launch.

1. Aerospace

Aerospace is PEEK's earliest application field. The particularity of aerospace requires flexible processing, low processing cost, and lightweight materials that can withstand harsh environment. PEEK could replace aluminum and other metals in aircraft parts because it is exceptionally strong, chemically inert and flame retardant, and can be easily molded into parts with very small tolerances.

Inside the aircraft, there have been successful cases of wire harness clamp and pipe clamp, impeller blade, engine room door handle, insulation covering film, composite fastener, tie wire belt, wire harness, corrugated sleeve, etc. External radome, landing gear hub cover, manhole cover, fairing bracket and so on.

PEEK resin can also be used to make batteries for rockets, bolts, nuts and parts for rocket engines.

2. Smart mattress

At present, the automotive industry increasingly requires the dual performance of vehicle weight, cost minimization and product performance maximization, especially people's pursuit of vehicle comfort and stability, the weight of the corresponding air conditioning, electric Windows, airbags and ABS braking system equipment is also increasing. The advantages of PEEK resin, such as good thermodynamic performance, friction resistance, low density and easy processing, are utilized to make auto parts. While the processing cost is greatly reduced, not only the weight can be reduced by up to 90%, but also the service life can be guaranteed for a long time. Therefore, PEEK, as a substitute of stainless steel and titanium, is used to manufacture the material of engine inner cover. Manufacturing automotive bearings, gaskets, seals, clutch rings and other components, in addition to the transmission, brake and air conditioning system applications are also many.

3. Electronics

VICTREX PEEK has the characteristics of high temperature resistance, wear resistance, corrosion resistance, low volatility, low extraction, low moisture absorption, environmental protection and flame retardant, size stability, flexible processing, etc. It is widely used in computers, mobile phones, circuit boards, printers, light-emitting diodes, batteries, switches, connectors, hard disk drives and other electronic devices.

4. The Energy industry

Choosing the right materials is often seen as one of the key factors for successful development in the energy industry, and in recent years VICTREX PEEK has become increasingly popular in the energy industry to improve operational performance and reduce the risk of downtime associated with component failure.

VICTREX PEEK is increasingly used by the energy industry for its high heat resistance, radiation resistance, hydrolysis resistance, self-lubrication, chemical corrosion resistance and excellent electrical performance, such as subsea integrated wiring harness pipelines, wires and cables, electrical connectors, downhole sensors, bearings, bushings, gears, support rings and other products. In oil and gas, hydropower, geothermal, wind power, nuclear energy, solar energy are applied.

APTIV™ films and VICOTE™ coatings are also widely used in the industry.

5. Other

In the mechanical industry, PEEK resin is commonly used to make compressor valves, piston rings, seals and various chemical pump bodies and valve parts. Using this resin instead of stainless steel to make impeller of vortex pump can obviously reduce the wear degree and noise level, and prolong its service life. In addition, modern connectors are another potential market because PEEK meets the specifications of pipe assembly materials and can be bonded at high temperatures using a variety of adhesives.

The semiconductor industry is developing towards larger wafers, smaller chips, narrower lines and line width sizes, etc. VI CTREx PEEK polymer material has obvious advantages in wafer manufacturing, front-end processing, processing and inspection, and back-end processing.

In the medical industry, PEEK resin can withstand up to 3000 cycles of autoclaving at 134 ° C, which makes it suitable for the manufacture of surgical and dental equipment with high sterilization requirements that require repeated use. PEEK resin can show high mechanical strength, good stress resistance and hydrolysis stability in hot water, steam, solvents and chemical reagents, etc. It can be used to manufacture a variety of medical devices requiring high temperature steam disinfection. PEEK not only has the advantages of light weight, non-toxic and corrosion resistance, but also is the material closest to human skeleton, which can be organically combined with the body. Therefore, using PEK resin to manufacture human skeleton instead of metal is another important application of PEEK in the medical field.

Ⅳ, Prospects

Along with the development of science and technology, people will be more and more high to the requirement of material, especially in the current energy shortage, the weight loss authors is every enterprise must consider the question, with plastic instead of steel is the inevitable trend of the development of materials for special engineering plastics PEEK the "universal" demand will be more and more, also will be more and more wide application field.