Коричнево желтый порошок POB 200 сетка может использоваться как материал системы передачи для авиационного оборудования

volume resistivity 1.2 × 10 · m, dielectric constant 3.5, dielectric loss tangent 3.5 × 10-3,
Electric strength 26mv / M;

its thermal decomposition temperature ，in air is as high as 530 ℃, and its thermal stability in
air is very high, 400 ℃ for 1H The thermal weight loss is only 1%, which can be used for a long time at 320 ℃ and for a short time
at 400 ℃ The thermal deformation temperature reaches 300 ℃ (pure PTFE is about 120 ℃ ) and can be used for a long time at 250 ℃;
the properties of the molded sample are: constant The bending strength at temperature is 50MPa, after 30h at 300 ℃ , it reaches
35MPa, and the compressive strength is > 100MPa;

 insoluble in all fat and aromatic solvents, resistant to various acids
and bases at room temperature, But it is easy to be eroded by hot acid and hot alkali;

 Brinell hardness 31mpa, compressive strength 106mpa and
bending strength 52Mpa (40MPa after aging at 300 ℃ for 151h), notchless impact strength of 1.47kj/m2, friction coefficient of 0.2
~ 0.3, dynamic friction The coefficient is 0.16 ~ 0.32. It can work for a long time without oil supply and has excellent
compression creep resistance. It is similar to polytetrafluoroethylene
The ultimate PV value of the blend alloy is 2500 kPa. / s, and its performance is far better than that of the best oil lubricated
porous bronze bearing and its wear rate in air and water is only 1 / 4 and 1 / 600 of that of glass fiber filled PTFE;

polyphenylene ester has the highest thermal conductivity among plastics (1.12w / K.M at 23 ℃ ),
which is higher than that of general plastics
Material height 3-5 times;

after 10gy60co irradiation, its bending strength is basically unchanged

 31 * 10-6 (1 / k), which makes its products have good dimensional stability.

With intrinsic flame retardancy, flexible polyimide foam produces almost no smoke and no functional properties when exposed to
open flames.
Toxic substances in barriers.

English Name: (polyphenylene ester)
Also known as: (polyoxybenzoyl, POB)
It is a polymer with p-oxbenzoyl repeating structural units in the main chain. The material is yellow to brownish yellow
crystalline powder.
It is an all aromatic polyester with the following molecular structure:
Polyphenylene ester is a linear chain molecule with high crystallinity (more than 90%) and is not easy to melt flow, so it has the
processing characteristics of thermosetting plastics.
Polyphenylene esters have properties very close to metals and exist in all plastics. It has the highest thermal conductivity and
thermal stability in air at high temperature
It also shows plastic flow similar to metal.

Polyphenylene ester is a highly crystalline (crystallinity greater than 90%) insoluble and immiscible linear polymer with many
excellent properties:
① Excellent electrical properties: volume resistivity is 1.2 × 1017 Ω • m, the dielectric constant is 3.5, and the dielectric loss
tangent is 3.5 × 10-3, strong dielectric
Degree is 26mv / M;
② High heat resistance: the thermal decomposition temperature in air is up to 530 ℃, and the thermal stability in air is high. The
thermal weight loss of 400 ℃ for 1 hour is only 1%, 320 ℃
Long term use, short-term use at 400 ℃. The thermal deformation temperature of products blended with PTFE is 300 ℃ (pure PTFE is
about 120 ℃), which can
Long term use at 250 ℃; The properties of the formed sample are:
The bending strength at room temperature is 50MPa, and it still reaches 35MPa after 300h at 300 ℃, and the compressive strength is
Strength > 100MPa;
③ Excellent solvent resistance and corrosion resistance: insoluble in all fat and aromatic solvents, resistant to various acids
and bases at room temperature, but easy to heat acids and hot bases
Erosion;
④ Excellent mechanical properties, wear resistance and self lubrication: Brinell hardness 31mpa, compressive strength 106mpa,
bending strength 52Mpa (300 ℃)
After 151h aging, it still reaches 40 MPa), the notch impact strength is 1.47 kJ / m2, the friction coefficient is 0.2 ~ 0.3, and
the dynamic friction coefficient is 0.16 ~ 0.32
It works without oil for a long time and has excellent compression creep resistance. When blending with polytetrafluoroethylene,
the limit value of PV can reach 2500 kpa.m/s
It far exceeds the lubrication performance of the best porous bronze bearing grease today (see Table 1 for the performance of PTFE
/ POB alloy), and the wear rate is higher in air or water
Is 1 / 4 and 1 / 600 of glass filled PTFE;
⑤ Excellent thermal conductivity: at present, polyphenylene ester plastics have the highest thermal conductivity (1.12w/km at 23 ℃
), which is 3-5 times higher than ordinary plastics;
⑥ Good radiation resistance: after 107 Gy60 Co irradiation, the bending strength is basically unchanged;
⑦ Low thermal expansion coefficient: 31 * 10-6 (1 / k),
The product has good dimensional stability

Polyphenylene ester must be dried at 150 - 250 ℃ for 2h before use, and the materials cannot be stacked too thick to prevent
thermal carbonization of the polymer.
Compared with other engineering plastics, polyphenylene ester is very similar to metal. It has crystallization transition at
330-380 ℃ and begins to show similar metal at 427 ℃
Inviscid flow. The forming methods are as follows:
① Blend with other engineering plastics into plastic alloy materials (such as PTFE, PI, PPS, peek, PAS, etc.). At present, the
most widely used is
PTFE / POB alloy (polyphenylene ester content is generally 15-40wt%). The alloy has both advantages and disadvantages. forming
Methods PTFE / POB alloy and PTFE filled products were sintered by cold pressing (see Annex);
② High pressure hot embossing rapid forging: forming temperature 350-380 ℃, pressure 50-150mpa, pressure holding time (according
to wall thickness) 5-15min, 150 ℃
Following ejection;
③ High temperature plasma spray molding: inert gas helium and argon are passed through the arc area to form helium or argon at
high temperature (3000-5000 ℃)
Ions are then rapidly introduced into polyphenylene ester powder. Under the action of high temperature plasma, certain pressure
and other strong energy, polyphenylene ester on the substrate surface
Form a dense coating with a thickness of 0.2-0.5mm;
Dispersing coating molding: dispersing polyphenyl ester powder into polytetrafluoroethylene emulsion and obtaining POB/PTFE
dispersion. Separation with polytetrafluoroethylene
The same coating process as the bulk solution.