Page 208 - Engineering Plastics Handbook

Chapter
9

Polyphenylene Ether (PPE)

Blends and Alloys

Edward N. Peters, Ph.D.
Principal Scientist
GE Plastics
Selkirk, New York, USA

Introduction

In 1956, Allan S. Hay of the General Electric Company discovered a con-
venient catalytic oxidative route to poly(2,6-dimethylphenylene ether), or
PPE. This amorphous polymer exhibited excellent hydrolytic stability, an
extremely high glass transition temperature [T = 419°F (215°C)], out-
g
standing electrical properties over a wide temperature range, low density
relative to other engineering thermoplastics, and a high melt viscosity. The
polymer was introduced commercially in 1964 under the PPO* trademark
[1, 2].
It was soon realized that because of the high glass transition tempera-
ture, high melt viscosity, and the resulting elevated temperatures that were
required for processing, it would be difficult to avoid oxidative degrada-
tion reactions during melt processing. The commercial solution to this
problem was blends of PPE with polystyrene (PS).
PPE may never have achieved commercial success if PPE’s novel com-
patibility with styrenic polymers had not been discovered at an early stage
of development. This fortuitous and rather rare miscible, single-phase

*Noryl, Noryl GTX, Noryl PPX, PPO, Noryl ETX, and Noryl EF are trademarks of the
General Electric Company.

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