A DFT-metadynamics study disclosing key properties of ring-opening polymerization catalysts to produce polyethercarbonate polyols from cyclic ethylene carbonate as part of an emerging CCU technology

Abstract

The ring opening polymerization of cyclic carbonates made from epoxide and CO2 to CO2-containing polymers constitutes an emerging technology of particular industrial interest. Considering the reaction of ring-opening polymerization of...

Catalytic Ring-Opening Polymerisation of Cyclic Ethylene Carbonate: Importance of Elementary Steps for Determining Polymer Properties Revealed via DFT-MTD Simulations Validated Using Kinetic Measurements

“…Our previous study considered the ring-opening polymerisation of cEC in the presence of the starter ROH, which begins with the proton abstraction from the starter ROH molecule by the catalyst anion (step I [ 46 ]). The generated RO − attacks the C=O group of the first neighbouring cEC.…”

“…This complexation delays the reaction in case of SnO 3 2− vs. VO 4 3− , 9.5 h vs. 5.0 h, respectively, in experiment, which is in accordance with the higher barrier of the cEC ring opening for SnO 3 2− vs. VO 4 3− ( Table 2 ). For a detailed analysis we refer to the [ 46 ]. In addition, the cation’s lability also plays a role in more efficient catalytic performance.…”

“…The results of the kinetic measurements and the rate constants are reported in Table 4 . The literature (also shown in Table 4 ) shows that the ROP of cEC catalysed by phosphate has lower CO 2 content in the final polymer (10% lower than K 3 VO 4 and Na 2 SnO 3 ) [ 46 ]. In addition to that, according to 31 P-NMR, insertion of phosphate is observed during the polymerisation ( 31 P NMR (500 MHz, CD 2 Cl 2 ) δ 17.84 (s, 1P), 1.64 (d, J = 169.7 Hz, 7P), 1.08 (s, 2P)), shown in Figure 8 .…”

Investigation and Comparison of Catalytic Methods to Produce Green CO2-Containing Monomers for Polycarbonates

“…Although replacing ethylene oxide with carbon dioxide makes ecological sense, this approach has not made its way to the market so far [2][3][4]. Further catalysts and variations in the product structures are still being researched today [2,3,[5][6][7][8][9][10][11][12][13][14]. The synthesis of CO 2 -containing polymers is still very challenging, aiming at the avoidance of high-energy costs during copolymerization and extreme conditions such as high temperatures and pressures.…”

“…The synthesis of CO 2 -containing polymers is still very challenging, aiming at the avoidance of high-energy costs during copolymerization and extreme conditions such as high temperatures and pressures. Using pre-formed CO 2 -containing monomers such as cyclic ethylene carbonate (cEC) opens up new possibilities in this area with ring-opening polymerizations (ROPs), whose reaction pathways are already better understood [7,8,10,15]. By using ROP, the incorporation of CO 2 is substantially increased in comparison to CO 2 /epoxide copolymerization, and therefore ensures significant savings in energy and raw materials.…”