A One‐Step Route to CO₂‐Based Block Copolymers by Simultaneous ROCOP of CO₂/Epoxides and RAFT Polymerization of Vinyl Monomers

Abstract

The one-step synthesis of well-defined CO 2 -based diblockc opolymers was achieved by simultaneous ring-opening copolymerization (ROCOP) of CO 2 /epoxides and RAFT polymerization of vinyl monomers using at rithiocarbonate compound bearing ac arboxylicg roup (TTC-COOH) as the bifunctional chain transfer agent (CTA). The double chaintransfer effect allows for independent and precise control over the molecular weight of the two blocks and ensures narrow polydispersities of the resultant blockcopolymers (1.09-1.14). Notably,anunusual axial group exchange reaction between the aluminum porphyrin catalyst and TTC-COOH impedes the formation of homopolycarbonates.Bytaking advantage of the RAFT technique,i ti sa ble to meet the stringent demand for functionality control to well expand the application scopes of CO 2 -based polycarbonates.

Aluminum Porphyrin Complex Mediated Auto-Tandem Catalysis for One-Pot Synthesis of Block Copolymers

“…We have previously reported that Cl − of PPNCl coordinates to Al, facilitates the dissociation of Al-O bonds, and therefore, accelerates ROCOP of CO 2 and epoxides. 53,62 As anticipated, the rate of PO/PA ROCOP decreased significantly without PPNCl (Table 1, entries 1 and 2). Yet, PPNCl showed no obvious effect on PET-RAFT polymerization of MMA.…”

“…This interesting phenomenon could be explained by the fast and quantitative axial group exchange reaction between the carboxylate group and (TPP 2-Cl )Al III -Cl, which leads to the rapid and quantitative formation of (TPP 2-Cl )Al III -O 2 C-PMMA (Scheme 3c). 53 Therefore, the ring-opening of PO occurs via nucleophilic attack of [PMMA- 3b), both PPE with alternating structure and PMMA formed in the reaction, while no signals corresponding to junction units could be observed. As determined by 1 H NMR spectroscopy, the conversions of both MMA and PA steadily increased with reaction time.…”

“…However, when azodiisobutyronitrile (AIBN) was employed as the exogenous radical resource, it is difficult to precisely manipulate the block compositions. 53 For the first time, we report that (TPP)Al III -X can serve as highly efficient and selective photoredox catalysts for PET-RAFT polymerization. Furthermore, the (TPP 2-Cl )Al III -Cl auto-tandem catalysis involving ROCOP of epoxides/anhydrides and PET-RAFT polymerization of vinyl monomers has been demonstrated, wherein the regulation of visible light permits on-demand sequence control over the block copolymer products (Scheme 1).…”

Recent advances in carbon dioxide utilization

“…The large-scale application of CO2 copolymers is still limited due to relatively low catalytic activity and poor thermal and mechanical properties. In past decades, there have been a large number of experimental and theoretical studies on the reaction mechanisms, catalytic efficiency, and the applications of polymers [53][54][55][56][57].…”

One-Pot Synthesis of Polyester-Based Linear and Graft Copolymers for Solid Polymer Electrolytes

“…In the one-pot synthesis of BCPs, we try the combination of RAFT polymerizations of methacrylate monomers (MMA, BMA, and PEGMA) or styrene and ROP of ε-CL. 69,70 our one-pot synthesis method uses ACVA bifunctional free radical initiator instead of traditional free radical initiators combined with ROP catalysts. (Figure 4).…”