1, PPO polyphenylene oxide, usually referred to as poly 2,6- two methyl -1,4- phenyl ether,

 or PPO (Polyphenylene Oxide), is a comprehensive thermal engineering plastic with excellent properties.

2, PPO synthesis: 2,6- two methyl -1,4- phenyl ether is formed by condensation reaction with 

oxygen under the action of copper amine catalyst. The structure of the PPO is as follows:

3, the relationship between the structure and the nature of PPO:
(a), aromatic ring makes the rotation of molecular chains difficult, so PPO has poor fluidity and poor processability.
(b), the methyl groups on benzene ring increase resistance and rigid structure, making PPO rigid, high hardness, 

high stability and strong chemical resistance.
(c), the PPO terminal group is phenoxy, so the thermal oxidation resistance is poor. The thermal stability of PPO

 material can be improved by blocking the ends of antioxidants or isocyanates.


4. Summarize the characteristics of PPO:


Excellent properties: high tensile strength, high modulus, high impact resistance, hardness and rigidity, hard and 

tough material, good creep resistance, good wear resistance, low friction coefficient, good heat resistance, heat 

deformation temperature of 190 degrees centigrade, glass transition temperature 210 centigrade, thermal 

decomposition temperature 350 degree centigrade, embrittlement -70 degree centigrade Hot wire expansion

 coefficient 4, good flame retardancy (no melting, self extinguishing), good water resistance (water content 0.03%,

 good boiling water resistance, high temperature water resistant products), density 1.06 grams per cubic

centimeter (experience: density 1.45 plus 40% filling material.) It has strong electrical insulation.


Shortcomings: poor fluidity, poor processing performance, expensive price, and easy cracking

 (so it is necessary to modify, currently used polyphenylene ether materials, most of the PPO modified materials).