Depolymerization of Poly(2,6-dimethyl-1,4-phenylene oxide) in Green Solvents: Water and Ionic Liquid

Abstract

The depolymerization of poly(2,6-dimethyl-1,4-phenyleneoxide) (PPO) was accomplished by employing 4-tert-butyl-2,6-dimethylphenol (TBDMP) and 2,6-dimethylphenol (DMP) under oxidative conditions in green solvents: water and ionic liquid. PPO depolymerized to oligomeric products in a faster process within 5 min with TBDMP and within 1 min with DMP in water. In addition to water, an ionic liquid mixture containing the 1-ethyl-3-methylimidazolium cation [C2mim] and a mixture of alkylbenzenesulfonate with xylene sulfonate anion [ABS] was used for the depolymerization of PPO. Depolymerization was successfully achieved in [C2mim][ABS] with TBDMP in a slower process within 3 h.