Aug 31 2001
Although unchanged PPO is a semi-crystalline thermoplastic, all commercially available grades are blended with (high impact) polystyrene in order to improve melt processability.
A broad range of proportions, along with the use of other modifiers, results in a good range of grades with varying properties tailor-made to the requirements of individual end-uses.
Advantages
Good rigidity, tensile strength, heat distortion temperature and increased maximum operating temperature combined with low warp and shrinkage compared with unmodified PPO.
These blends are opaque, amorphous, pale grey engineering thermoplastics with a balance of properties (and cost) not unlike nylon but without nylon's high water absorption and resulting dimensional instability.
However, they have poor fatigue features and poor solvent, though good hydrolysis, resistance.
Disadvantages
Reduced elongation at break and notched izod impact strength compared with unmodified PPO. Physical properties of moulding can be highly anisotropic.
Applications
Polyphenylene Oxide can be used in the automotive industry, for components in heating systems, radiator and expansion tanks, bulb sockets, mirror housings, air inlet and outlet grills. PPO can also be used as a metal replacement in pumps and components for central heating systems.
Other applications include;
- washing and dish-washing machine parts,
- electrical and TV components,
- automobile parts (particularly fascias)
- structural foam
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Image Credit: ShutterStock/Bachtub Dmitrii
Typical Properties
| Property |
Value |
| Density (g/cm3) |
1.27 |
| Surface Hardness |
RR130 |
| Tensile Strength (MPa) |
120 |
| Flexural Modulus (GPa) |
9 |
| Notched Izod (kJ/m) |
0.1 |
| Linear Expansion (/°C x 10-5) |
2.5 |
| Elongation at Break (%) |
3 |
| Strain at Yield (%) |
N/A |
| Max. Operating Temp. (°C) |
90 |
| Water Absorption (%) |
0.06 |
| Oxygen Index (%) |
26 |
| Flammability UL94 |
HB |
| Volume Resistivity (log ohm.cm) |
17 |
| Dielectric Strength (MV/m) |
15 |
| Dissipation Factor 1 kHz |
0.01 |
| Dielectric Constant 1 kHz |
2.9 |
| HDT @ 0.45 MPa (°C) |
165 |
| HDT @ 1.80 MPa (°C) |
158 |
| Material. Drying hrs @ (°C) |
2 @ 100 |
| Melting Temp. Range (°C) |
250 - 300 |
| Mould Shrinkage (%) |
0.2 |
| Mould Temp. Range (°C) |
80 - 110 |
Source : Abstracted from Plascams
For more information on Plascams please visit RAPRA Technology Ltd.