Alcoholysis of oxyphenylene-based super engineering plastics mediated by readily available bases

Abstract

Herein we describe the alcoholysis of super engineering plastics under mild conditions. Treatment of polysulfone (PSU) with methanol mediated by sodium hydroxide in 1,3-dimethyl-2-imidazolidinone (DMI) at 80 °C resulted in facile depolymerization to form bis(4-methoxyphenyl)sulfone and 4,4’-(propane-2,2-diyl)diphenol (bisphenol A) in high yields. These products were readily isolated by simple filtration. The DMI solvent effectively promoted depolymerization and allowed insoluble resins such as polyetheretherketone (PEEK) to undergo the reaction. This method was applicable to other alcohols, such as ethanol and isopropyl alcohol. The depolymerization of super engineering plastics such as polysulfone (PSU) smoothly proceeded in the presence of methanol mediated by sodium hydroxide in 1,3-dimethyl-2-imidazolidinone (DMI) at 80 °C to form bis(4-methoxyphenyl)sulfone and 4,4’-(propane-2,2-diyl)diphenol (bisphenol A) in high yields. These products were readily isolated by simple filtration. The DMI solvent effectively promoted depolymerization and allowed insoluble resins such as polyetheretherketone (PEEK) to undergo the reaction. This method was applicable to other alcohols, such as ethanol and isopropyl alcohol.