Degradation of Super Engineering Plastics Into Monomeric Products Toward Chemical Recycling

Abstract

Super engineering plastics, high-performance thermoplastic resins such as polyetheretherketone (PEEK) have been utilized as advanced materials in industries such as aircrafts, automobiles, and medical devices, owing to their high thermal stability, chemical resistance, insolubility, and mechanical strength. However, their robustness hinders their chemical recycling, or degradation, to produce oligomers or monomeric chemicals. Chemical recycling of PEEK has been particularly difficult, to the extent that it is considered impossible. To overcome this drawback, we have researched on the chemical recycling of super engineering plastics and related robust resins. Herein, we report our recent research topics on the chemical recycling of super engineering plastics: base-catalyzed degradation of super engineering plastics such as PEEK using thiols to form dithiobenzophenones and hydroquinone without collapsing the molecular architectures of the main chain. This degradation method was applicable to various super engineering plastics including polysulfone, polyethersulfone, and polyetherimide.