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MPPE
Overview
Modified polyphenylene ether(MPPE) is an alloy of high impact polystyrene(HIPS) and polyphenylene ether(PPE) which is also called as polyphenylene oxide(PPO). This high-performance engineering plastic offers outstanding dielectric properties, mechanical properties, heat resistance and flame retardance. Pure polyphenylene ether(without the addition of HIPS, nylon or similar resins) is a thermoplastic with a glass transition temperature at least 200กษ.
When PPE was first developed in the 1960s, molding machines that could efficiently process this kind of resin had yet to be designed and end-users did not require PPE with high heat resistance. For these reasons, creating an exclusive market for PPE was difficult. Another shortcoming: Even though it features excellent dielectric properties and heat resistance, surface cracks will appear in molded plastic products made from PPE if the molding conditions are not just right.
Modified PPE(MPPE or modified PPO) was developed to make up for these shortcomings, to improve processability and to better satisfy users' needs. The heat resistant character of MPPE is slightly less than that of pure PPE, but the modified version has better procesability and higher impact resistance. MPPE provides the advantages of PPE in finished products, so a large market has been created for it. With application temperature ranging from -40กษ to 150กษ, MPPE offers outstanding processability.
MPPE maintains good creep resistance and its low moisture absorption allows excellent dimensional stability. Superior dielectric and magnetic properties, and a low expansion coefficient are combined with outstanding self-extinguishing and non-drip properties, so obtaining flame retardance is relatively easy and resistance to hydrolysis is good.
MPPE is available in general heat resistant, flame retardant and heat resistant, general glass fiber reinforced, and flame retardant glass fiber reinforced grades.
Features
1) Mechanical Properties
- Temperature dependency
Among engineering plastics, MPPE offers a superior balance of tensile strength, impact strength, flexural strength & modulus, and heat resistance. One of its unique features is the wide range of temperatures under which it can be processed.
- Creep resistance
For plastic products to be used as structural materials, they must maintain their set shape when exposed to a specified load for a long period. Plastics are viscoelastic, so the creep phenomenon occurs. MPPE boasts excellent creep resistance, even though it is a thermoplastic.
- Warpage
The dimensional precision and dimensional stability of plastic must be excellent if it is to be used in place of metal. MPPE provides some of the best warp resistance of any thermoplastic. It boasts exceptional linear expansion coefficient anisotropy and post injection molding shrinkage anisotropy.
- Recyclability
Defective MPPE molded products (including sprues, runners, etc.) can be ground up and reused. However, during this process, their physical properties would have been altered. Therefore, the amount of reused material in the mix must be kept below a predetermined ratio.
2) Dielectric Properties
MPPE exhibits outstanding dielectric properties as an engineering plastic. The dielectric loss tangent and dielectric constant are virtually unaffected by temperature, humidity or (radio) frequency. The volume resistivity and surface resistivity both are high values, reducing the effects of temperature and humidity. This makes MPPE well suited for use as an insulation material.
3) Heat Resistance
PPE has a low moisture absorption rate and has excellent properties for (curbing) hydrolysis which prevails in esters such as polybutylene terephthalate or polycarbonate that are bonded with it.
4) Chemical Resistance
PPE is not easily permeated by acids or alkaline substances, and hydrolysis does not readily occur. However, caution must be exercised because PPE is affected by chlorohydrocarbons and aromatic hydrocarbons.
5) Flame Retardance
These days, using halogen elements such as bromine or chlorine for flame retardant mechanisms is raising concerns over the dangers halogens pose to the human body and to the environment. Flame retardant grade MPPE is a non-halogen material used to supplement in place of antimony compounds, which have been proven harmful to the human body. Finally, the specific gravity of MPPE is lower than that of other flame retardant resins.
Table 1. Properties and applications of staren MPPE by grade
| Class |
Grade |
Characterization |
Typical Application |
| General |
HR-8054 |
|
Heat
Resistant Parts, Automobile Interiors, Pipe Fitting |
|
HR-8054M |
|
HR-8074 |
High
Heat Resistance |
Bobbin
for Thread |
|
Flame Retardant |
VB-8062E |
High
Heat Resistance, High Reflectance,
MPPE/TiO 2 25%
|
LED
Reflector |
|
VB-8064 |
High
Heat Resistance |
Adapter,
Connector, DY Case |
|
FR-8074 |
High Heat Resistance |
DY
Case, FBT Case |
| Reinforced/
General |
GP-8100G |
High Flexural Strength, GF 10% |
Impeller
and Pump Housing |
|
GP-8200G |
High
Flexural Strength, GF 20% |
Printer
Frame, Tray |
|
GP-8300G |
High
Flexural Strength, GF 30% |
|
Reinforced/
Flame Retardant |
VB-8102G |
High Flexural Strength, GF 10% |
Bobbin |
VB-8202G |
High
Flexural Strength, GF 20% |
OA
Equipment, Bidet Water Tank, Impeller and Pump Housing |
| VB-8300G |
High
Flexural Strength, GF 30% |
PPE/Nylon |
HT-8010 |
High
Heat Resistance, Printability |
Wheel
Cap, Handle and Fender For Automobile |
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| © 2010 SAMSUNG CHEMICAL (USA), INC. |
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