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A novel functional polycarbonate (PAGC), characterized by the presence of double bonds within its side chain, was successfully synthesized through a ternary copolymerization of propylene oxide (PO), allyl glycidyl ether (AGE), and carbon dioxide (CO2). Polyhedral oligomeric silsesquioxanes octamercaptopropyl (POSS-SH) was employed as a crosslinking agent, contributing to the formation of organic–inorganic hybrid materials. This incorporation was facilitated through thiol-ene click reactions, enabling effective interactions between the POSS molecules and the double bonds in the side chains of the polycarbonate. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirmed a homogeneous distribution of silicon (Si) and sulfur (S) in the polycarbonate matrix. The thiol-ene click reaction between POSS-SH and the polycarbonate led to a micro-crosslinked structure. This enhancement significantly increased the tensile strength of the polycarbonate to 42 MPa, a notable improvement over traditional poly (propylene carbonate) (PPC). Moreover, the cross-linked structure exhibited enhanced solvent resistance, expanding the potential applications of these polycarbonates in various plastic materials. [ABSTRACT FROM AUTHOR]

Construction of CO2‐based amphiphilic block copolymers (ABCs) is an efficient method for providing CO2‐based polycarbonates with self‐assembly properties in aqueous media. It is challenging to construct CO2‐based ABCs by one‐step strategies from mixed monomers because hydrophilic blocks, usually composed of polar monomers, have negative effects on the synthesis of polycarbonates. In this work, we report a one‐step method to construct CO2‐based ABCs obtained by simultaneous ring‐opening copolymerization (ROCOP) of CO2/epoxides and reversible addition‐fragmentation chain transfer (RAFT) polymerization of N‐isopropyl acrylamide (NIPAM). A trithiocarbonate/carboxy compound was used as the bifunctional chain transfer agent, and an aluminum porphyrin complex was used as the catalyst for ROCOP, which proved to be efficient in CO2 copolymerization even in the presence of NIPAM with strong polarity. This strategy allows flexible control over the molecular weight (5–16 kg/mol) and the hydrophilic‐hydrophobic balance (HLB 9–18) of the ABCs, and ensures narrow polydispersity Đ (1.1–1.3) of the polymers. The ABCs can further self‐assemble into micelles in water with controllable diameters and reversible phase transformation behavior with temperature changes from 25 to 40 °C. This simple route to CO2‐based ABCs with multiple functions has large potential in biomedical applications. [ABSTRACT FROM AUTHOR]

As a powerful protocol for the preparation of common polymers, such as polyolefins, polyesters, and polycarbonates, late-transition-metal-catalyzed polymerization can be carried out by controlling the reaction conditions or developing dynamic catalytic systems that use external stimuli to influence the performance of the active sites, resulting in well-defined polymeric materials. In particularly, under the latter conditions, 'one catalyst' can provide more than one kind of polymer with a controlled sequence from the monomer mixture, making full use of the prepared catalyst. In this review, tunable modes, including reaction conditions, redox, light or electrochemical properties, Lewis acids, and alkali metal cations, of late-transition-metal-complex (especially iron, cobalt, and nickel)-catalyzed polymerization were collected and thoroughly discussed. [ABSTRACT FROM AUTHOR]

A series of vanadium(V) aroylhydrazine‐arylolates is employed in ethylene polymerization to produce ultra‐high molecular weight polyethylene (UHMWPE), surprisingly extending to such coupling reactions beyond their common usage in the oxidation of hexanes and alcohols. Activated by either MAO or DMAC, the complexes V1–V3 efficiently catalyze the polymerization of ethylene into UHMWPE, that is, with an activity up to 3.37 × 106 g mol−1 h−1 (60°C) and the polyethylene obtained has a molecular weight around 3 million g mol−1, being the highest molecular weight achieved by a vanadium catalyst so far. More importantly, the significant effects of different cocatalysts are well illustrated; the catalytic system with MAO generally shows lower activity with almost one order in the magnitude than that with DMAC (0.43 vs. 3.37 × 106 g mol−1 h−1), but the polyethylenes with higher molecular weights are obtained by the system with MAO. [ABSTRACT FROM AUTHOR]