Controlled molecular weight by the precipitation polymerization of 2,6-dimethylphenol

Low molar mass poly(2,6-dimethyl-1,4-phenylene-ether)s (PPE) have been prepared by the precipitation polymerization of 2,6-dimethylphenol (DMP) under the action of a Cu(I)Cl/amine-catalyst and O2. The polymers prepared possess a rather narrow molecular weight distribution (D = 1.7-2.2), and the molecular weight can easily be controlled by adjusting the solvent mixture of 2-propanol and toluene. Molecular weights were determined using 1H-NMR spectroscopy, GPC, and FD-MS, and range from M n = 2700 to 7500 g/mol. No Mannich-basetype endgroups and no incorporation of DPQ (3,5,3',5'-tetramethyl-4,4'-diphenoquinone) has been detected