Direct Copolymerization of CO2 and Diols

Abstract

Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 α,ω-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification.

CO2 Conversion with Alcohols and Amines into Carbonates, Ureas, and Carbamates over CeO2 Catalyst in the Presence and Absence of 2‐Cyanopyridine

“…In addition, picolinate‐capped cooligomers were also observed, which may be a cause for the low molecular weight. This method is also applicable to various diols including linear C4–C10 α,ω‐diols to give high yields of the corresponding cooligomers (Table ), which cannot be obtained by well‐known methods such as copolymerization of CO 2 and cyclic ethers and ring‐opening polymerization of cyclic carbonates.…”

“…Another interesting profile of the results of CO 2 +1,3‐propanediol+2‐cyanopyridine is the reaction time dependence (Figure ), where the experimental method was similar to that in our previous report on the synthesis of polycarbonate from CO 2 +diols+2‐cyanopyridine . At short reaction time, the selectivity of cyclic trimethylene carbonate was high, however, it decreased with increasing the reaction time.…”

“…Next, we used 1,4‐butanediol and the results of CO 2 +1,4‐butanediol+2‐cyanopyridine using CeO 2 catalyst is shown in Figure . The reaction was conducted in autoclave reactor with 10 mmol 1,4‐butanediol, 5 MPa CO 2 (at r.t.), 2‐cyanopyridine 100 mmol, and 0.17 g CeO 2 at 433 K. Here, the formation of the cyclic carbonate from CO 2 +1,4‐butanediol was not almost detected, and the formation of polycarbonates was detected by SEC.…”

Direct Catalytic Synthesis of N‐Arylcarbamates from CO2, Anilines and Alcohols

“…Therefore, development of catalyst systems which can sophisticatedly control the reactivities of the three components and overcome the equilibrium limitation is desirable. Recently, we found that combination of CeO 2 and 2‐cyanopyridine was an effective catalyst system for the synthesis of dimethyl carbonate (DMC) from CO 2 +CH 3 OH and cyclic carbonates and polycarbonates from CO 2 +diols. Urakawa and co‐workers also applied the combination catalyst system to the DMC synthesis at high CO 2 pressure .…”

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

“…At present the ring‐opening polymerization of six‐membered cyclic carbonate monomers, commonly derivatives of trimethylene carbonate (TMC, IUPAC: 1,3‐dioxan‐2‐on) and the polycondensation of dialkyl carbonates with diols are the established pathways for the synthesis of functional aliphatic polycarbonate (PCs) . Furthermore, the direct polymerization of CO 2 and diols was described in the literature . For the synthesis of poly(trimethylene carbonate) (PTMC) and poly(dimethyl trimethylene carbonate) functional polymer analogs, cyclic carbonates bearing a variety of functional groups have been developed ( Figure ) .…”