Views: 0 Author: Rio Liang Publish Time: 2026-05-12 Origin: Site
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● 1.Quick preview of their differences
● 2. PEEK (Polyetheretherketone)
● 3. PPS (Polyphenylene Sulfide)
● 4. ULTEM \ PEI (Polyetherimide)
● 4. PPSU (Polyphenylene Sulfide)
● 5. PSU
Special engineering plastics are types of plastics that possess outstanding properties such as high strength, high temperature resistance, corrosion resistance, and wear resistance. However, today we will only discuss five common thermoplastic materials: PEEK, ULTEM, PPSU, PSU, and PPS.
Each of them has its own unique properties. They are suitable for producing different products. I wrtie this article to show their properties and characteristics, you can use this information to select the appropriate high-performance plastics for your product.
Writer Opinion:
"The processing of thermoplastic materials is relatively simple, with high production efficiency and suitability for secondary processing. Moreover, their storage period is also longer.PEEK&PEI&PPSU&PPS are strong thermoplastic"2026-05-12
—————— Rio Liang/Business Manager|PEEK&PEI&PPSU&PPS SUPPLIER FROM CHINA
| Material | PEEK | PPS | PEI | PPSU | PSU |
| Appearance | Gray (Semi-crystalline) | Crystalline | Amorphous | Amorphous | Amorphous |
| Color | maize-yellow | white/maize-yellow | Amber Transparent | Light Yellow Transparent | Transparent |
| Continuous Service Temp. | 260°C | 180°C | 220°C | 180°C | 150°C |
| Toughness / Impact(BASE ON RESIN) | TOP2 | TOP3 | TOP5 | TOP1 | TOP4 |
| Inherent Flame Retardancy | V-0(1.45mm) | V-0 (0.4mm) | V-0 (0.8mm) | V-0 | V-0 |
| LOI(Limiting Oxygen Index) | 35% | 47% | 44% | 44% | 30% |
These five are all high-performance special engineering plastics. They have different temperature resistance levels, transparency, toughness, and chemical/hydrolysis resistance.
PEEK has excellent comprehensive performance but is the most expensive; PPS is corrosion-resistant and cheaper, but has lower toughness; PEI is transparent and resistant to high temperatures, with excellent electrical properties. PPSU and PSU belong to transparent polysulfone types, with different using temperatures and sterilization requirements.
Writer Opinion:
"I think, PEEK material is currently the highest comprehensive performance thermoplastic material ".2026-05-12——— Rio Liang
PEEK material is a semi-crystalline polymer, commonly used in aerospace, high-end medical implants, and semiconductor fixtures, among other fields.
The toughness and fatigue resistance of PEEK resin are extremely outstanding. It can operate under long-term alternating stress and has the best resistance to load fatigue among all plastics. Its peel resistance and crack resistance are also very excellent.
The high-temperature resistance of PEEK material is very good. It can withstand 260°C for a long time and 300°C for a short period. Although it is slightly lower than PI material, if we also need to consider the processing difficulty, PEEK material is better. The processing temperature of PEEK is wider than that of PI material and is easier to process.
Glass fibers and carbon fibers are usually used to enhance its heat distortion temperature, wear resistance, and mechanical strength.
It also has other excellent properties:
Chemical corrosion resistant
Wear resisatnce
"cost-effectiveness and corrosion resistance". PPS is a crystalline polymer that is inherently flame-retardant (reaching V-0 level without flame retardants), has excellent corrosion resistance to acids and bases, has similar chemical resistance to PTFE, and has a very low water absorption rate. It is commonly used in automotive sensors, pump valve casings, and electronic connectors. Currently, the largest usage is in new energy vehicles.
It has high hardness and is the plastic most similar to metal. The strength of PPS resin is relatively low, and it usually requires glass fibers for reinforcement. The PPS material of PRES contains 30%-60% glass fibers, and its performance is already sufficient to meet the needs of most products, with a significant increase in impact strength and dimensional stability.
"High-temperature transparency and durability". PEI material is amorphous and amber transparent, with excellent dimensional stability. It naturally has flame retardancy (LOI 47%)， and has a long-term operating temperature of approximately 170°C. It is commonly used in internal components of mobile phones， aircraft interiors， and high-temperature connectors.
The electrical properties of polyphenylene ether resin are extremely outstanding. It can maintain insulation at high temperatures, and its loss factor is small, meaning that the signal transmitted through the polyphenylene ether material experiences very little loss, making it suitable for 5G communication applications.
PEI is also often reinforced with glass fibers to enhance its mechanical strength. PEI GF30 can withstand greater loads at high temperatures without deforming.
Due to its excellent high-temperature resistance, we reinforced it with carbon fibers to give it anti-static properties. Anti-static PEI does not experience significant changes in resistance due to temperature increases.
PPSU materials are commonly used in food contact, medical devices, and laboratory equipment.
Its transparency is higher than that of PEI materials, and its impact resistance is extremely excellent. PPSU products are unlikely to be damaged even when dropped from a height.
Another very important feature of PPSU is that it does not contain BPA, making it a very safe material. It is often used to make baby bottles and bowls for BABIES.
It has an extremely strong ability to withstand high-temperature steam sterilization (high-pressure sterilization), which is its biggest selling point. It can withstand 500 to 1000 cycles under standard steam at 121°C; under more stringent 134°C high-temperature steam, it can usually withstand 100 to 800 cycles without significant deformation, cracking, or substantial decline in mechanical properties.
It has excellent performance in chemical disinfection: it has good tolerance to common disinfectants in medical scenarios such as alcohol (ethanol/isopropanol), hydrogen peroxide, sodium hypochlorite, iodophor, and most acid and alkali cleaning agents. It is not prone to stress cracking or surface degradation when in long-term contact.
It is compatible with a variety of mainstream disinfection/sterilization methods: in addition to high-temperature steam, it also withstands gamma ray irradiation, ethylene oxide (EtO), peracetic acid, etc., and has high hydrolytic stability, making it highly suitable for reusable equipment that requires frequent cleaning and disinfection.
"Transparent and resistant to high temperatures". PSU material long-term working temperature 160°C, it has good electrical properties, but its resistance to steam sterilization is not as good as PPSU (about 300 times less), and its toughness is slightly inferior. It is commonly used in food utensils, circuit boards and membrane materials.
