Modified Polyphenylene oxide (PPO) and Modified Polyphenylene Ether (MPPE) Characteristics and applications

Modified polyphenylene oxide (PPO) or MPPE (modified polyphenylene ether) is widely used in the market. Traditionally, polyphenylene oxide and its modified blend polymer are called PPO or PPE.

Characteristics and Applications

PPO is a kind of thermoplastic engineering plastics with excellent comprehensive properties, outstanding electrical insulation and water resistance, and good dimensional stability.

1. The dielectric property ranks first in engineering plastics

PPO resin has no strong polar groups in its molecular structure, has stable electrical properties, and can maintain good electrical properties in a wide range of temperature and frequency.

① Dielectric constant: 2.6-2.8 is the smallest in engineering plastics ② dielectric loss tangent: 0.008-0.0042 (almost not affected by temperature, humidity and frequency) ③ volume resistivity: 1016 is the highest in engineering plastics

2. Good mechanical and thermal properties PPO molecular chain contains a large number of aromatic ring structures, strong molecular chain sensibility, high mechanical strength of the resin, excellent creep resistance and little influence of temperature change. PPO has high heat resistance, with a glass transition temperature of 211 ℃ and a melting point of 268 ℃.

3. Excellent water resistance PPO is an amorphous resin. In the normal temperature range, it has little molecular movement, no large polar groups in the main chain, no polarization of dipole moment, and very good water resistance. It is the variety with the lowest water absorption in engineering plastics. After soaking in hot water for a long time, its physical properties still have little decline.

4. It has good flame retardancy. The oxygen index of PPO with self extinguishing property is 29, which is a self extinguishing material, while the oxygen index of high impact resistant polyethylene is 17, which is a flammable material. The combination of the two is of medium flammability. When manufacturing flame retardant grade PPO, halogen flame retardant does not need to be added, and the flame retardant dose containing phosphorus can reach UL94 standard to reduce environmental pollution.

5. Low shrinkage and good dimensional stability; Non toxic, low density 6, medium resistance and light resistance PPO is basically free from corrosion to acids, alkalis and detergents. Under stress, mineral oil and ketone and ester solvents will produce stress cracking; Organic solvents such as aliphatic hydrocarbons, halogenated aliphatic hydrocarbons and aromatic hydrocarbons will melt and dissolve.

The weakness of PPO is poor light resistance. It changes color and turns yellow when used in sunlight or fluorescent lamp for a long time. The reason is that ultraviolet can split the chain of aromatic ether. How to improve the light resistance of PPO has become a subject.

The performance of PPO determines its application field and scope:

① MPPO has the advantages of low density, easy processing, thermal deformation temperature of 90-175 ℃, commodities of different specifications and good dimensional stability. It is suitable for manufacturing office equipment, household appliances, computer box, chassis and precision parts.

② The dielectric constant and dielectric loss tangent of MPPO are the lowest among the five general engineering plastics, that is, it has the best insulation and good heat resistance. It is suitable for the electrical industry. It is suitable for making electrical insulating parts used under wet and loaded conditions, such as coil framework, pipe seat, control shaft, transformer shielding sleeve, relay box, insulating pillar, etc.

③ MPPO has good water resistance and heat resistance. It is suitable for manufacturing yarn tubes for water meters, water pumps and textile factories. It needs durable consumer goods to cook. The yarn tubes made of MPPO have a long service life.

④ The dielectric constant and dielectric loss tangent of MPPO are not affected by temperature and cycle number in engineering plastics, and have good heat resistance and dimensional stability. It is suitable for electronic industry.

⑤ Due to the development of electronic industry and communication industry, mobile phones, portable computers, high-performance cameras and cameras all need lithium-ion batteries. Therefore, the lithium-ion battery market has great development prospects. The packaging materials of organic electrolyte for lithium-ion batteries used to use ABS or PC. recently, MPPO for batteries has been developed abroad, and its performance is better than the first two.

⑥ MPPO is widely used in the automotive industry, such as instrument dial, protective bar, etc. PPO and PA alloys, especially specifications and varieties with high impact resistance, are used for external decorative parts, and the invention is relatively fast.

⑦ Chemically, modified polyphenylene oxide can be used to manufacture corrosion-resistant equipment. It has particularly good hydrolysis resistance, acid and alkali resistance, and is cheap to dissolve in aromatic and chlorinated hydrocarbons.

⑧ For medical devices, it can replace stainless steel and other metals in the mixed packing valve of hot water tank and exhaust fan.