Aliphatic polycarbonate synthesis by copolymerization of carbon dioxide with epoxides over double metal cyanide catalysts prepared by using ZnX2 (X=F, Cl, Br, I)

CO2-fixation into cyclic and polymeric carbonates: principles and applications

“…53 Zinc glutarate and other zinc carboxylates are industrially relevant, as they are easy to handle, non-toxic, air-stable and economically viable. 2,6 Double metal cyanide catalysts [Zn 3 (M(CN) 6 ) 2 , where the most commonly employed metals are M = Co(III) or Fe(III)] 52,53 show high activity for polymerisation reactions with a variety of epoxides, including propylene oxide [196][197][198] and cyclohexene oxide ( Table 6, entry 13), 191,196,198 but they exhibit low CO 2 uptake and commonly yield poly(ether carbonates) rather than pure polycarbonates. 53 In contrast to homogeneous catalytic systems, heterogeneous catalysts such as zinc carboxylates and double metal cyanides generally need more extreme reaction conditions for epoxide/CO 2 polymerisations, namely a high CO 2 pressure.…”

Dinuclear Metal Complex-Mediated Formation of CO2-Based Polycarbonates

“…Typical values for carbonate linkages in PPC are in the range of 20-40%, whilst those for PCHC can reach 90% [22,118,126]. Moreover, the copolymerisation conditions require high pressures of CO 2 (50-100 atm) [21,22,118,126]. Finally, the copolymer molecular weights were moderate (10,000-30,000 g/mol), with large dispersities as would be expected from multisite initiators.…”

Effect of Zn/Co initial preparation ratio in the activity of double metal cyanide catalysts for propylene oxide and CO2 copolymerization

“…As a kind of potential approach, one of the most promising areas for CO2 is its application as a material for polymer synthesis [6]. Without the intention of competing against natural CO2 fixation in flora, polycarbonates can be synthesized through the technologically viable process of CO2 fixation by coupling CO2 and epoxides with the presence of hetero or homogeneous catalysts [7], [8], [9].…”

“…In this sense, the past three decades it has attested a great progress in the fixation of CO2 into polycarbonates. Since the pioneering work of Inoue in 1969 using ZnEt2/H2O as a catalyst [11], many systems have been reported and demonstrated effective utilization of CO2 where the importance of a catalyst has never been overestimated [12], [13], [6,7].…”

“…DMC catalyst generally referred to zinc hexacyanometalate prepared by reaction of zinc halide and hexacyanometalate salt [3] and a complexing agent in some cases [5]. These complexes are considered to be effective not only for propylene oxide ring-opening (ROP) but also for CO2-epoxides copolymerization [6,7,9,13,14]. The catalysts are highly active and give polyether polyols that have low unsaturation and narrow molecular weight distribution [6], yielding biodegradable polycarbonates with a wide potential for polyurethane applications [15].…”