Rate and classification of heat resistance of plastic - you need to understand common sense
Compared to traditional materials such as metals, ceramics and glass, one of disadvantages of plastics is their low heat resistance, which often limits their use at high temperatures.
In plastic materials, different types of plastics have different heat resistance: some have very low heat resistance, while others have a higher one. Heat-resistant plastics generally refer to a class of plastic products with a heat distortion temperature above 200°C.
There are three indicators for measuring heat resistance of plastic products: thermal deflection temperature, Martin heat resistance temperature and Vicat softening temperature, among which thermal deflection temperature is most commonly used.
The relationship between above three heat resistance indices of same plastic is as follows: Vicat softening temperature＞thermal distortion temperature＞Martin heat resistance temperature
According to heat resistance of plastics, plastics are divided into following four categories:
①Low temperature plastics are resins with a thermal deformation temperature of less than 100°C. Specific varieties include: PE, PS, PVC, PET, PBT, ABS and PMMA, etc.
②Medium heat-resistant plastics are a type of resin with a thermal deformation temperature of 100 to 200 °C. Specific varieties are: PP, PVF, PVDC, PSF, PPO and PC etc.
③ High temperature resistant plastics are a type of resin with a thermal deformation temperature of 200 to 300 °C. Specific varieties: heat distortion temperature of polyphenylene sulfide (PPS) can reach 240°C, heat distortion temperature of chlorinated polyester can reach 210°C, heat distortion temperature of polyarylsulfone (PAR) can reach 280°C, and heat distortion temperature of PEEK can reach 210°C. The heat warp temperature can reach 230°C, heat warp temperature of POB can reach 260-300°C, heat warp temperature of fusible PI can reach 270-280°C, heat warp temperature of aminoplast can reach 240°C, and heat warp temperature of EP can reach 230°C℃, PF thermal distortion temperature can reach 200℃.
④Super high temperature resistant plastics are a type of resin with a thermal deformation temperature of more than 300°C. There are several types, in particular: thermal distortion temperature of polyphenylene can reach 310°C, thermal distortion temperature of polybenzimidazole (PBI) can reach 435°C, and thermal distortion temperature of infusible PI can reach 360°C.
Which one is most resistant to high temperatures?
The long-term working temperature of polybenzimidazole PBI can reach 310 ° C, and short-term use temperature canreach 500 ° C. Polybenzimidazole PBI is one of most heat-resistant plastics, but price is also highest among plastics, and processing is difficult. Therefore, most heat-resistant plastic is polybenzimidazole PBI.
Secondly, most heat-resistant plastic should be PI polyimide. Long-term working temperature can reach about 290°C, and short-term working temperature can reach 480°C. It can work in -240°C environment.
Other materials resistant to high temperatures
PAI (also known as TORLON) is also a type of thermosetting plastic. Long-term working temperature can reach 250℃, and excellent low temperature resistance. TORLON also has excellent wear and impact resistance. .
PEEK, long-term working temperature can reach 160°C, short-term working temperature can reach 260°C, improved grade has better high temperature resistance.
Polyetherimide PEI, long-term working temperature can reach 170℃, and short-term working temperature can reach 200℃.
The long-term working temperature of PPS polyphenylene sulfide can reach 220℃, and short-term working temperature can reach 260℃.
PVDF long-term working temperature can reach 150°C, and short-term working temperature can reach 160°C. It also has excellent corrosion resistance, high mechanical strength and rigidity.
PTFE has a long-term working temperature of 260°C and a short-term working temperature of 280°C. It has excellent corrosion resistance and is widely known as "King of Plastics". It also has an extremely low coefficient of friction.
The long-term working temperature of polysulfone power supply is 150°C, and short-term working temperature can reach 180°C. The polysulfone power supply also has good comprehensive electrical properties. The performance of PES is similar to that of PSU, and working temperature is higher, long-term working temperature is 180°C, and short-term working temperature is 220°C.
Nylon 46, long-term working temperature can reach 135℃, with excellent toughness and good chemical resistance.