This communication reports on vinyl polymers capable of selective and fast main-chain scission (MCS). The trick is the domino reaction in an alternating sequence of methyl 2-(trimethylsiloxymethyl)acrylate and 5,6-benzo-2-methylene-1,3-dioxepane, a cyclic ketene acetal for radical ring-opening polymerization. Removal of the trimethylsilyl group using BuN·F readily led to MCS via irreversible transesterification of the ester backbone, affording a five-membered lactone fragment. The molar mass decreased drastically within 5 min, and no side reactions were observed. Control experiments suggest that the formation of a five-membered ring via a domino reaction is critical for fast and selective MCS. The terpolymers with methyl methacrylate and styrene also exhibited a large decrease in molar mass within 5 min. In addition, MCS was also observed for the heterogeneous reaction system in acidic aqueous media; treatment of the binary copolymer in a 50 wt % acetic acid solution resulted in a significant decrease in molar mass after 30 min. These results suggest efficient construction of degradable sites using a binary monomer system corresponding to the pendant trigger and ester backbone. Because this molecular design using a binary monomer system provides selective and fast MCS for terpolymers containing other vinyl monomers, it can provide various degradable vinyl polymers.
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Sci Rep
January 2025
Department of Zoology, Faculty of Science, Cairo University, Giza, Egypt.
Plastic pollution and global warming are widespread issues that lead to several impacts on aquatic organisms. Despite harmful studies on both subjects, there are few studies on how temperature increases plastics' adverse effects on aquatic animals, mainly freshwater species. So, this study aims to clarify the potential impact of temperature increases on the toxicological properties of polyvinyl chloride nano-plastics (PVC-NPs) in Nile tilapia (Oreochromis niloticus) by measuring biochemical and oxidative biomarkers.
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January 2025
Nanotechnology Department, Faculty of Science, Urmia University, Urmia, Iran.
Today, active packaging has become essential to increase food safety and decrease food spoilage. In this study, the aim was to delay spoilage and increase the shelf life of rainbow fish fillets with a new hybrid nanocomposite active packaging. Packaging was fabricated with Ethylene vinyl acetate and active compounds such as rosemary extract, zinc oxide nanoparticles, and modified iron (Fe-MMT).
View Article and Find Full Text PDFEnviron Pollut
January 2025
Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares, Madrid, Spain.
Plastics, as synthetic polymers, are emerging contaminants that can harm organisms and ecosystems. This study investigates the presence of microplastics in sediments of two rivers in western Cuba, assessing their temporal variability, diversity, and characterizing the types of microplastics in these ecosystems. Additionally, the study examines the relationship between microplastic concentrations, the extracellular enzymatic activity of benthic microbial communities, and nutrient levels in sediments.
View Article and Find Full Text PDFLangmuir
January 2025
Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 315211 Ningbo, P. R. China.
Solar-driven desalination technology is currently an important way to obtain freshwater resources. Significantly, porous materials are used as substrate materials of interface solar evaporator, and their specific impact of water transport property and thermal management during evaporation is worth exploring. In this paper, poly(vinyl alcohol) (PVA) sponges were prepared by a chemical foaming method, adjusted the PVA polymerization degree, and formaldehyde-hydroxyl ratio to regulate the pore size, and polypyrrole (PPy) was grown in situ on the surface skeleton of PVA sponge to construct a new interfacial solar evaporator (PPy/PVA) with different pore structures.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Chang Chun Institute of Applied Chemistry Chinese Academy of Sciences, Key Laboratory of Polymer Ecomaterials, 5625 Renmin Street, Changchun, , 130022, Changchun, CHINA.
Living cationic polymerization (LCP) is a classical technique for precision polymer synthesis; however, due to the high sensitivity of cationic active species towards chain-transfer/termination events, it is notoriously difficult to control polymerization under mild conditions, which inhibits its progress in advanced materials engineering. Here, we unlock a practical anion-binding catalytic strategy to address the historical dilemma in LCP. Our experimental and mechanistic studies demonstrate that commercially accessible hexafluoroisopropanol (HFIP), when used in high loading, can create higher-order HFIP aggregates to tame dormant-active species equilibrium via non-covalent anion-binding principle, in turn inducing distinctive polymerization kinetics behaviors that grant efficient chain propagation while minimizing competitive side reactions.
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