Methanolysis of Plastic Waste with Manganese Compounds

This work describes a very efficient methodology for the methanolysis of polyester and polycarbonate plastic waste into a variety of valuable products using homogeneous and heterogeneous manganese compounds in the presence of KO^tBu. Excellent yields are obtained using 1 mol% of the homogeneous catalysts Mn(OTf)₂, Mn₂(CO)₁₀, MnBr(CO)₅, and MeCpMn(CO)₃ and 5 mol% of KO^tBu, under mild reaction conditions. The heterogeneous manganese catalyst, manganese(II) ethyl/butyl phosphonate silica (Si-Mn), also successfully promoted the methanolysis of polyester and polycarbonate plastic waste with excellent yields. Furthermore, this heterogeneous catalyst can be applied in at least 12 catalytic cycles with excellent yields.