Special engineering plastics, also known as high-performance polymers, have better and more unique performance than general engineering plastics, and long-term use temperature is above 200℃. Application of special engineering plastics has gradually extended from previous military and aerospace fields to more and more civilian fields, such as automobiles, equipment manufacturing, high-end consumer goods, etc. Among them, polyphenylene sulfide (PPS) and polyetheretherketone (PEEK) are two special engineering plastics with relatively rapid development and a wide range of applications. I briefly introduces characteristics and differences of the two materials. You can consider them comprehensively based on use conditions, performance requirements and cost budget of your own products.
PEEK and PPS can be classified as crystalline thermoplastics. Their natural color is beige. They have good dimensional stability, can resist erosion by various media, and have excellent chemical resistance. Fire retardant grade is UL94-V0, and they have good electrical insulation properties. They are commonly used in electronics, machinery, automobiles, flame retardant accessories, and other fields.
From perspective of mechanical properties, PEEK is superior to PPS in terms of strength, toughness, maximum operating temperature, etc. On the other hand, PPS has a very obvious cost advantage and better processing performance, making its application range more extensive. Its global production capacity and annual compound growth rate are among best in thermoplastic special engineering plastics. Due to continuous increase in usage and continuous expansion of application areas, PPS is now known as sixth largest engineering plastic after PA, PC, PBT/PET, POM and PPO.
Polyetheretherketone resin (PEEK) is a special polymer material with excellent comprehensive properties such as self-lubrication, high temperature resistance, good flame retardancy, corrosion resistance, hydrolysis resistance, wear resistance and fatigue resistance. It can replace traditional materials such as ceramics and metals in many special fields. It is mainly used in aerospace, automotive industry, electronic appliances, semiconductors and medical equipment. Parts such as bushings, sleeves, seals, and support rings are used in aircraft, oil field drilling and other equipment. They are made of PEEK to improve performance and reliability.

 

Polyphenylene sulfide resin (PPS) is a crystalline new high-performance thermoplastic resin with excellent high temperature resistance, corrosion resistance, radiation resistance, flame retardancy, mechanical properties, dimensional stability and excellent electrical properties. As a polymer structural material, it is widely used in electronic appliances, automobiles, mechanical chemicals and other fields. It is one of the best heat-resistant varieties in engineering plastics. For example, automotive parts such as pump housings, impellers, connectors, thermostats, sensors, EGR valves, etc. have successfully replaced metals thanks to excellent performance of PPS materials, making cars more lightweight.

 

PEEK is a polyetheretherketone plastic, which is polymerized from ether, ketone and olefin. Characteristics of its molecular structure make PEEK have excellent heat resistance, chemical corrosion resistance and mechanical properties.
PPS is a polyphenylene sulfide plastic, which is composed of alternating benzene rings and sulfur atoms. Molecular structure of PPS gives it good electrical insulation, chemical corrosion resistance and high temperature stability.

Density: Density of PEEK is slightly higher than that of PPS, which makes it more advantageous in some applications that require high strength and light weight.
Heat resistance: PEEK has higher thermal stability and can maintain excellent performance in high temperature environments. PPS may undergo oxidative degradation at high temperatures.
Mechanical properties: PEEK has excellent strength and rigidity and can withstand large pressure and tensile forces. Mechanical properties of PPS are relatively weak.
Electrical insulation: PPS has good electrical insulation properties, is suitable for fields of electronics and electrical appliances. Electrical insulation properties of PEEK are poor.

PEEK is mainly used in aerospace, automobile manufacturing, electronic appliances, medical and other fields because it has excellent heat resistance, mechanical properties and chemical stability.
PPS is widely used in electronic appliances, automobile manufacturing, chemical industry and other fields because it has good electrical insulation, chemical corrosion resistance and high temperature stability.
In applications requiring high strength and high temperature resistance, PEEK may be a better choice; while in applications requiring good electrical insulation and chemical corrosion resistance, PPS may be more suitable.
PEEK is superior to PPS in strength, toughness, maximum operating temperature, etc. In terms of high temperature resistance, PEEK's temperature resistance is about 50℃ higher than PPS. On the other hand, PPS's relatively obvious cost advantage and better processing performance make its application range more extensive.