A Guide to PPE

What is PPE?

The letters PPE stand for polyphenylene ether. Polyphenylene ether is a polymer characterized by regular, closely spaced phenyl groups (the same circular structures that are in polycarbonate). In general practice, PPE will indicate that a material is a modified polyphenylene ether. The modification of PPE involves the blending of a second polymer which is usually polystyrene or polystyrene/butadiene. PPE is similar in chemical composition to polyphenylene oxide (PPO), and they are generally treated as equivalent materials.

What are the properties of PPE?

very good physical properties
good heat resistance
poor chemical resistance
very stable dimensionally
poor color stability
opaque
moderate price
somewhat tough processing

What are the applications of PPE?

The strength, stability, and the acceptance of flame retardants of PPE (and PPO) makes them desirable for machine and appliance housings. The lack of chemical resistance and color stability means they often have to be painted in these applications. Low water absorption leads to their use in many water handling products. PPE can also be electroplated in automotive wheel covers and grills. Here is a summary of PPE applications:

internal appliance components
brackets and structural components of office products
large computer and printer housings (painted, foamed)
automotive wheel covers, plated
high tolerance electrical switch boxes and connectors