Efficient oxidative coupling polymerization for synthesis of thermosetting poly(phenylene ether) copolymer with a low dielectric loss

A novel oxidative coupling polymerization using a water/toluene heterogeneous system for the synthesis of thermosetting Poly(phenylene ether) copolymer (Allyl-PPE) was developed. Allyl-PPE with a narrow molecular weight distribution and a low copper content was obtained in the presence of a Cu/TMEDA catalyst dissolved in water droplets. This method solved the problems during the synthesis of the Allyl-PPE with conventional Cu/pyridine catalysts. The resulting Allyl-PPE exhibited excellent dielectric properties (ε′ = 2.4, tan δ = 0.002 at 10 GHz), and it will be useful for applications to high-speed and high-frequency printed circuit boards.