A single-step route to telechelic polyethylene (PE) is enabled by selective insertion polymerization. Pd -catalyzed copolymerization of ethylene and 2-vinylfuran (VF) generates α,ω-di-furan telechelic polyethylene. Orthogonally reactive exclusively in-chain anhydride groups are formed by terpolymerization with carbic anhydride. Combined experimental and theoretical DFT studies reveal the key for this direct approach to telechelics to be a match of the comonomers' different electronics and bulk. Identified essential features of the comonomer are that it is an electron-rich olefin that forms an insertion product stabilized by an additional interaction, namely a π-η interaction for the case of VF.
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http://dx.doi.org/10.1002/anie.201607754 | DOI Listing |
ACS Nano
October 2024
Department of Chemistry, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, Mainz D-55128, Germany.
J Am Chem Soc
October 2024
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Creating C═C bonds as "weak" sites in the stable C-C chains of polyethylene (PE) is an appealing strategy to promote sustainable development of the polyolefin industry. Compared to methods, such as dehydrogenation and postpolymerization modification, the copolymerization of ethylene (E) and butadiene (BD) should be a convenient and direct approach to introduce C═C bonds in PE, whereas it encounters problems in controlling the composition and regularity of the copolymer due to the mismatched activities and mechanisms between the two monomers. Herein, we report by employing the amidinate gadolinium complex, controllable E/BD copolymerization was achieved, where BD was incorporated in the uniformly discrete 1,4 mode.
View Article and Find Full Text PDFJ Am Chem Soc
August 2024
Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.
Polyolefins are recognized as fundamental plastic materials that are manufactured in the largest quantities among all synthetic polymers. The chemical inertness of the saturated hydrocarbon chains is crucial for storing and using polyolefin plastics, but poses significant environmental challenges related to plastic pollution. Here, we report a versatile approach to creating polyethylene materials with tunable degradability by incorporating in-chain mechanophores.
View Article and Find Full Text PDFBiomacromolecules
July 2024
Department of Chemistry and Biology "Adolfo Zambelli" University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy.
A backbone-substituted N-heterocyclic carbene (NHC) zinc complex, in combination with alcohol initiators, has been shown to be an effective catalyst for the ring-opening polymerization (ROP) of trimethylene carbonate (TMC) to poly(trimethylene carbonate) (PTMC) devoid of oxetane linkages. The ROP of TMC proceeded in solution to give PTMC, possessing controlled molecular mass (2500 < < 10000) and low dispersity ( ∼ 1.2).
View Article and Find Full Text PDFJ Am Chem Soc
June 2024
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-68, 100 44 Stockholm, Sweden.
Antibiotic-resistant pathogens have been declared by the WHO as one of the major public health threats facing humanity. For that reason, there is an urgent need for materials with inherent antibacterial activity able to replace the use of antibiotics, and in this context, hydrogels have emerged as a promising strategy. Herein, we introduce the next generation of cationic hydrogels with antibacterial activity and high versatility that can be cured on demand in less than 20 s using thiol-ene click chemistry (TEC) in aqueous conditions.
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