Alternating copolymerization of CO2 with propylene oxide and terpolymerization with aliphatic epoxides by bifunctional cobalt Salen complex

Abstract

A novel N,N¢-[2,2¢-bis(nitrilomethylidyne)]bis[a-methyl-4-(morpholin-1-ylmethyl)-6-tert-butyl phenolato]-1,2-diaminocyclohexane Co III (2,4-dinitrophenoxy) complex (complex 1) was designed and used to couple carbon dioxide (CO 2 ) and propylene oxide (PO) as a single-component catalyst. Systematic investigation revealed that complex 1 was highly active and selective in the coupling of CO 2 /PO and that complete consumption of PO was accomplished with high copolymer selectivity. A high molecular weight of up to 108.6 kg mol À1 was achieved with an appropriate combination of all variables. Matrix-assisted laser desorption ionizationtime-of-flight mass spectrometer analysis implied that a chain-end control mechanism controls the copolymerization. In addition, complex 1 could operate very efficiently in the terpolymerization of PO and cyclohexene oxide (CHO) with CO 2 to provide polycarbonates with a narrow polydispersity. The Tg of the PO/CHO/CO 2 terpolymer can be easily adjusted between 40 and 118.9 1C.

Synthesis of vegetable-oil based polymer by terpolymerization of epoxidized soybean oil, propylene oxide and carbon dioxide

“…Surprisingly in this study, the weight percentage of the cyclic carbonate in the product was found to decrease with increasing reaction temperature. This is in contrast with the report mentioned elsewhere where stated that the formation of thermodynamically stable cyclic carbonate is highly favored at higher reaction temperature (Li and Niu, 2011). Another important finding was that the signal of ether unit becomes more significance at higher reaction temperature (Supplementary A3).…”

Dinuclear Metal Complex-Mediated Formation of CO2-Based Polycarbonates

“…The area of catalyst development brings together the fields of organometallic and polymer chemistry. This review has highlighted the development of catalysts from the early days of the field, when zinc alkoxide and carboxylate clusters were the mainstay of research, through the development of successful single-site metal complexes, and beyond to the study of kinetics and [15,38,93,179] mechanism to inform the preparation of the current bimetallic catalysts. These mechanistic studies have implicated bimetallic active sites in many cases, although there do remain other examples where monometallic mechanisms appear dominant, most notably for metal porphyrins used with cocatalysts.…”

Functional Polycarbonates from Carbon Dioxide and Tailored Epoxide Monomers: Degradable Materials and Their Application Potential

“…Variation of the polymer properties can also be achieved by terpolymerization of cyclohexene oxide (CHO) and PO with carbon dioxide (CO 2 ) . In contrast to the brittle behavior of PCHC (elongation at break of 1–2%), PPC exhibits higher flexibility (elongation at break between <10 and 1200% with a median around 600% depending on the used catalyst and polymerization conditions), but its low T g (30–40 °C) clearly limits its use .…”