A novel approach to RE–OR bond from in situ reaction of rare earth triflates and sodium alkoxides: A versatile catalyst for living ring-opening polymerization of ε-caprolactone

Recent Advances in the Enzymatic Synthesis of Polyester

Polyester is a kind of polymer composed of ester bond-linked polybasic acids and polyol. This type of polymer has a wide range of applications in various industries, such as automotive, furniture, coatings, packaging, and biomedical. The traditional process of synthesizing polyester mainly uses metal catalyst polymerization under high-temperature. This condition may have problems with metal residue and undesired side reactions. As an alternative, enzyme-catalyzed polymerization is evolving rapidly due to the metal-free residue, satisfactory biocompatibility, and mild reaction conditions. This article presented the reaction modes of enzyme-catalyzed ring-opening polymerization and enzyme-catalyzed polycondensation and their combinations, respectively. In addition, the article also summarized how lipase-catalyzed the polymerization of polyester, which includes (i) the distinctive features of lipase, (ii) the lipase-catalyzed polymerization and its mechanism, and (iii) the lipase stability under organic solvent and high-temperature conditions. In addition, this article also focused on the advantages and disadvantages of enzyme-catalyzed polyester synthesis under different solvent systems, including organic solvent systems, solvent-free systems, and green solvent systems. The challenges of enzyme optimization and process equipment innovation for further industrialization of enzyme-catalyzed polyester synthesis were also discussed in this article.

Solid electrolytes for solid-state Li/Na–metal batteries: inorganic, composite and polymeric materials

This feature article presents the electrolyte synthetic approaches, design strategies, and merging materials that may address the critical issues of solid electrolytes for solid-state Li/Na–metal batteries.

Ring-Opening Polymerization of CO2-Based Disubstituted δ-Valerolactone toward Sustainable Functional Polyesters

3-Ethylidene-6-vinyltetrahydro-2H-pyran-2-one (EVL) is a disubstituent δ-lactone derived from CO₂ and 1,3-butadiene. In this contribution, we report the ring-opening polymerization (ROP) of EVL with β-butyrolactone (BBL) as the comonomer catalyzed by scandium triflate [Sc(OTf)₃]. The obtained polyester bearing active unsaturated bonds has the weight-average molecular weight (M_w) of 4.1 kg/mol, in which the EVL content is 38 mol % in accordance with the initial ratio of 40 mol %. The copolymers are characterized in detail and the cationic ROP mechanism has been confirmed by kinetic study, chain end analysis and density functional theory (DFT) calculation. The modification of the unsaturated bonds in EVL repeating units via the thio-ene click reaction with mercapto-ended polysarcosine polysarcosine yields the amphiphilic grafting polymers. It is a CO₂ fixation approach toward the functional poly(EVL-r-BBL) that is promising as a degradable polyester precursor for adhesive or surface-coating materials.

Synthesis and properties of poly(1,3-dioxolane) in situ quasi-solid-state electrolytes via a rare-earth triflate catalyst

We report a rare-earth triflate catalyst Sc(OTf)3 for the ring-opening polymerization of 1,3-dioxolane and the in situ production of a quasi-solid-state poly(1,3-dioxolane) electrolyte, which not only demonstrates a superior ionic conductivity of 1.07 mS cm-1 at room temperature, but achieves dendrite-free lithium deposition and a high Coulombic efficiency of 92.3% over 200 Li plating/striping cycles.

Zwitterionic copolymerization of γ-butyrolactone with 3,3-bis(chloromethyl) oxacyclobutane catalyzed by scandium triflates

Zwitterionic copolymerization of γ-butyrolactone with 3,3-bis(chloromethyl) oxacyclobutane is catalyzed by scandium triflates generating random linear and cyclic copolymer.

Living cationic ring-opening polymerization of 2-oxazolines initiated by rare-earth metal triflates

Lewis acidic rare-earth metal triflates were found to efficiently initiate the cationic ring-opening polymerization of 2-oxazolines in a multi-site propagating fashion.