What is high temperature engineering plastics?

PPO

PPO (polyphenylene oxide) is an amber transparent material with a specific gravity close to water of 1.06.

1. Combustion characteristics

It is hard to burn, it is extinguished after the fire, the flame is thick black smoke, and the fruit is stinky when the plastic melts.

2, the biggest advantage

It has the highest glass transition temperature of 210 ° C in thermoplastic plastics, so its high temperature resistance is very high. High temperature resistant PPO plastic has the ability to boil water at high temperature without deformation or decomposition. PPO is hard and tough and has high creep resistance. Its surface hardness is higher than PA/POM/PC, creep is lower than these three materials; it has good elongation at -135 ° C low temperature; dimensional stability. High temperature resistant PPO plastics can be metallized, ie can be electro- or vacuum-coated. High temperature resistant PPO plastics have excellent dielectric properties and can be kept constant over a wide range of frequencies, temperatures and humidity.

3, shortcomings

In the case of organic solvents, PPO will exhibit stress cracking; PPO is not weather-resistant and is susceptible to discoloration under sunlight; PPO has poor fluidity and is difficult to process.

4, use

Due to the above advantages, PPO is most suitable for use in wet and loaded situations, that is, it requires excellent dielectric properties, high mechanical properties, and dimensional stability, such as tuning sheets, microwave insulation, and the like. Water treatment equipment, water distillation equipment, water pump parts, retort equipment, such as medical equipment, food materials, electrical rigidity of high rigidity and strength, and other parts, it is a more advanced shell material than PC.

5, injection molding performance

PPO is a crystalline plastic with a distinct melting point and melts at 217 ° C, but its viscosity is large, it is difficult to flow efficiently, it decomposes at 360 ° C; the general processing temperature is 280 ° C -340 ° C; PPO absorbs water, in the presence of moisture In the case, it can cause decomposition and needs to be dried. It can be dried at 140 ° C for 2-4 hours.

In addition, NORYL is a modified product of PPO. Compared with PPO, its mechanical properties are much lower, but it can partially replace PC.

PPS

PPS (polyphenylene sulfide) is a white material with high crystallinity, hard and brittle, excellent thermal stability, and can be characterized by high resistance of thermosetting plastics. Pure PPS can't be injection molded because it is too viscous and not easy to flow. The PPS for injection molding has been modified, and many fillers and modifiers have been added, which means that the PPS for injection molding is modified PPS.

1. Combustion characteristics

Non-combustible, extinguished after leaving the fire. But when they beat each other, they made a metal-like "jingle" sound.

2, the biggest advantage

At higher temperatures, it can withstand any solvent corrosion; PPS has high creep resistance and other mechanical properties; PPS can maintain its mechanical properties and size at high temperatures; PPS has excellent dielectric properties. It can be kept constant at a wide frequency, temperature and humidity.

3, shortcomings

PPS has poor fluidity and is difficult to process.

4, use

Due to the above advantages, PPS is most suitable for insulation, corrosion protection and insulation under high temperature and humidity and load.

5, injection molding performance

PPS is a crystalline plastic with a distinct melting point and melts at 280 ° C, but its viscosity is large, it is difficult to flow efficiently, it decomposes at 400 ° C; the general processing temperature is 300 ° C -340 ° C; PPO absorbs water, in the presence of moisture In the case, it can cause decomposition and needs to be dried. It can be dried at 140 ° C for 2-4 hours.

PSF

PSF is a microstrip amber transparent material (some PSF is an ivory opaque material) with a medium specific gravity of 1.24.

1. Combustion characteristics

It is hard to burn, extinguished after the fire, and the flame is yellow-brown smoke. The plastic burns and melts while giving off the burnt smell of rubber.

2, the biggest advantage

It has outstanding high temperature resistance and low temperature resistance; it can maintain 80% of its mechanical strength at 150 °C, and maintain its mechanical strength at -100 °C, 75% of its mechanical strength; PSF has outstanding creep resistance This makes it maintain various mechanical strengths; PSF has outstanding high-temperature dielectric properties, and maintains dielectric properties in water and moisture at 190 ° C; PSF has outstanding radiation resistance; PSF It can be metallized, that is, it can be coated by electricity or vacuum.

3, shortcomings

PSF does not undergo hydrolysis, but at high temperatures and loads, water causes it to stress crack. PSF has poor fluidity and is difficult to process.

4, use

Due to the above advantages, PSF is best suited for the manufacture of electrical and electronic components with tight tolerances, rigidity, thermal stability and good electrical insulation properties. PSF is best suited for the manufacture of parts that require thermal performance, chemical resistance, durability, and rigidity. PSF is not easily hydrolyzed at low temperatures. It can also be used to make parts for low-temperature water treatment equipment, parts for water pumps, water valves, and accessories for washing machines. It is a high-rigidity housing material that is more advanced than PC.

5, injection molding performance

The injection temperature of PSF is 280-320 °C, the modified PSF is similar to the PC injection molding conditions, and the baking temperature is similar to that of PC.