Hydrogenative Depolymerization of End-of-Life Poly-(Bisphenol A Carbonate) Catalyzed by a Ruthenium-MACHO-Complex

Abstract

The valorization of waste to valuable chemicals can contribute to a more resource-efficient and circular chemistry. In this regard, the selective degradation of end-of-life polymers/plastics to produce useful chemical building blocks can be a promising target. We have investigated the hydrogenative depolymerization of end-of-life poly(bisphenol A carbonate). Applying catalytic amounts of the commercial available Ruthenium-MACHO-BH complex the end-of-life polycarbonate was converted to bisphenol A and methanol. Importantly, bisphenol A can be reprocessed for the manufacture of new poly-(bisphenol A carbonate) and methanol can be utilized as energy storage material.

Keywords: catalysis; depolymerization; green chemistry; polymers; recycling.

Scheme 1

Concept for the chemical recycling of 1 via hydrogenation.

Scheme 2

Depolymerization of poly(bisphenol A carbonate) 1 originated from a DVD [Reaction conditions: 1  b/1  c (6.82 mmol, based on the monomeric unit), 5 (0.5 mol %, 0.0341 mmol based on the repeating unit of 1  a), THF (50.0 mL), 80 °C, 16 h, 45 bar H₂).