BIPHASIC SYNTHESIS OF POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE) USING A SURFACE-ACTIVE COUPLING CATALYST

A novel biphasic reaction technique has been developed which makes use of a surface-active complexing agent to draw the metal catalyst to the oil-water inteface where it affects the desired reaction. The surface-active ligand enables the catalyst to be "anchored" (and, therefore, recovered) at the oil-water interface. At the same time it permits the catalyst the flexibility to take up a configuration most favorable to the reaction. The technique thus offers the possibility of catalyst recovery while retaining the advantages of homogeneous catalysis, namely, high reactivity and reproducibility. Additionally, the new technique offers other advantages, including circumvention of solubility incompatability between reactant and catalyst, elimination of the use of a noxious or environmentally troublesome solvent that may otherwise be needed, and a rate enhancement. The feasibility and some of the advantages of the technique were demonstrated on the coupling synthesis of poly-(phenylene oxide), a commercially important polymer. It was shown that the biphasic technique and the use of a surface-active copper complex allowed the polymer to be synthesized from 2,6-dimethylphenol under mild reaction conditions. Molecular weight on the order of 50000 and a yield in excess of 80% were obtained. The necessary attributes of the surface-active ligand and the details of the reaction kinetics are reported.