Polyphenylene Oxide (PPO)

n A thermoplastic, linear, non-crystalline polyether obtained by the oxidative polycondensation on 2,6-dimethylphenol in the presence of a copper-amine complex catalyst. The resin has a wide useful temperature range, from below −170° to + 190°C, with intermittent use to 205°C possible. It has excellent electrical properties, unusual resistance to acids and bases, and is processable on conventional extrusion and injection-molding equipment. Because of its high coat PPO is also marketed in the form of polystyrene blends (see NORYL®) that are lower-softening (T_g of PS is about 100°C vs. 208°C for PPO), and have working properties intermediate between those of the two resins.