Views: 635 Author: Site Editor Publish Time: 2021-10-08 Origin: Site
Polysulphones, polyphenylsulphones and polyethersulphones are the high performance plastic widely used in many different industries. Do you know their relationship and how they differentiate?
Polysulfone, also known as PSF or PSU, usually refers to the thermoplastic polymers that an aryl-SO2-aryl subunit. These polymers have high performance, great rigidity, excellent high temperature resistance, and good stability under high temperature. In 1965, the polysulfone was industrialized by US Union Carbide for the first time. Due to the high cost of raw materials and difficult processing, polysulfone is generally used for applications with very demanding materials. In particular, it is also an advanced substitute for polycarbonate.
In most cases, PSU can refer to Bisphenol A Polysulfone. The common types of polysulfone also include polyethersulfone(PES) and polyphenylenesulfone(PPSU). Therefore, what is the difference between these high performance polymers?
Bisphenol A PSU
Bisphenol A polysulfone is synthesized from bisphenol A and 4,4´-dichlorodiphenyl sulfone through salt formation and polycondensation. The isopropylidene group can reduce the intermolecular force, and give the polymer a certain degree of flexibility and good melt processability. The non-polar methyl side chain makes the polymer less hygroscopic and its electrical performance improved. However, this would be bad for the heat resistance of the polymer, which can cause the Tg, the heat distortion temperature and maximum continuous use temperature of PSU to be lower than those of PPSU and PES.
Various synthetic methods for polyethersulfone are available, including melt desalination, dehydrochlorination, and solution desalination.
Compared with PSU, the macromolecular backbone of PES does not contain the isopropylidene groups that are unfavorable to heat resistance and thermal oxygen stability.
Compared with PPSU, the molecular backbone of PES does not have the biphenyl that makes molecular chains too rigid. Instead, it retains the diphenylsulfone group that makes polysulfone plastics have high heat resistance, thermal oxygen stability, mechanical properties and electrical insulation as well as ether groups that can give polysulfone good processability.
Therefore, PES have both advantages of PSU and PPSU, and it has better comprehensive performance than PSU and PPSU. Particularly, it has higher heat resistance than PSU and has greater processability than PPSU. PES can be processed by general thermoplastic processing methods. Thus, it is known as the first engineering plastic that combines high heat distortion temperature, high impact strength and the top molding processability.
Polyphenylenesulfone is synthesized from 4,4´-biphenol and 4,4´-dichlorodiphenyl sulfone through salt formation and polycondensation.
Compared with PSU, the molecular chain of PPSU does not contain isopropylidene but contains a large amount of biphenyl. Therefore, PPSU has higher heat resistance. However, the ether bond in the molecular chain can still provide a certain degree of flexibility, making it available to be used at a low temperature of -240°C. What’s more, the rigidity of the PPSU molecular chain is much higher than that of the PSU. As a result, withh higher melt viscosity is higher and worse melt fluidity it is more difficult to process PPSU.
The three high performance polymers can retain good mechanical strength, high heat resistance and creep resistance.
Especially, as one of the most widely used thermoplastic polymers, PES finds it applications in many different industries, such as filter membrane, non-stick coating, industrial molding, etc.
Polima is an experienced high-tech enterprise that mainly produce high-quality PES materials including PES resin granule, PES resin powder, modified PES resin. If you want to know more about us, feel free to contact us at office@polima.com.cn.