While functionalized polyethylenes (PEs) exhibit valuable characteristics, the constraints of existing synthetic approaches limit the variety of readily incorporated functionality. New methods to generate functionalized PEs are required to afford new applications of this common material. We report 100 % atom economic tantalum-catalyzed hydroaminoalkylation of vinyl-terminated polyethylene (VTPE) as a method to produce amine-terminated PE. VTPEs with molecular weights between 2200-16800 g/mol are successfully aminated using solvent-free conditions. Our catalytic system is efficient for the installation of both aromatic and aliphatic amines, and can be carried out on multigram scale. The associating amine functional groups afford modified material properties, as measured by water contact angle, differential scanning calorimetry (DSC) and polymer rheology. The basic amine functionality offers the opportunity to convert inert PE into stimuli-responsive materials, such that the protonation of aminated PE affords the generation of functional antibacterial PE films.
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http://dx.doi.org/10.1002/anie.202410154 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada.
While functionalized polyethylenes (PEs) exhibit valuable characteristics, the constraints of existing synthetic approaches limit the variety of readily incorporated functionality. New methods to generate functionalized PEs are required to afford new applications of this common material. We report 100 % atom economic tantalum-catalyzed hydroaminoalkylation of vinyl-terminated polyethylene (VTPE) as a method to produce amine-terminated PE.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Department of Chemistry, The University of Warwick, Coventry CV4 7AL, United Kingdom. Electronic address:
Hypothesis: Graphene Oxide (GO)-templated deposition of inorganic materials through synthesis on dispersed single sheets of GO is often complicated by the loss of the desired 2D morphology owing to the coagulation of GO sheets at high salt concentrations and non-templated homogenous nucleation. Modifying GO with anionic polymer is expected to solve both problems by i) enhancing electrostatic(steric) stabilization upon exposure to high concentrations of the ionic precursors, and ii) offering additional nucleation sites at the grafted anionic moieties to avoid homogeneous secondary nucleation.
Experiments: GO was grafted with branched copolymers of poly(ethylene glycol) methacrylate (PEGMA 500) and diethylene glycol dimethacrylate (DEGDMA) and ω-vinyl terminated methacrylic acid macromonomer (P(MAA)), the latter serving as an addition-fragmentation chain transfer agent.
Food Res Int
May 2024
Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Family and Consumer Sciences, North Carolina Agriculture and Technology State University, Greensboro, NC 27401, United States. Electronic address:
Leafy green surface microbiology studies often experience significant variations in results due to the heterogeneous nature of leaf surfaces. To provide a precise and controllable substitute, we microfabricated double-sided artificial leafy green phylloplanes using polydimethylsiloxane (PDMS) with a vinyl-terminated polyethylene glycol chain-based hydrophobicity modifier (PDMS-PEG) to modify PDMS hydrophobicity. We further tested the properties and applications of these artificial leaves, by examining the function of epicuticular wax, growth and survival of E.
View Article and Find Full Text PDFRSC Adv
December 2021
Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
A set of five related bis(imino)-6,7-dihydro-5-quinoline-cobalt(ii) complexes, [2-(ArN = CPh)-8-(NAr)-CHN]CoCl (Ar = 2,6-MeCHCo1, 2,6-EtCHCo2, 2,6-i-PrCHCo3, 2,4,6-MeCHCo4, 2,6-Et-4-MeCHCo5), have been synthesized in reasonable yield by the template reaction of cobalt(ii) chloride hexahydrate, 2-benzoyl-6,7-dihydro-5-quinolin-8-one and the corresponding aniline. The molecular structures of Co1 and Co4 highlight both the differences in the two imino-carbon environments (phenyl-capped chain cyclic) and also the steric properties exerted by the bulky -aryl groups. On pre-treatment with either modified methylaluminoxane (MMAO) or methylaluminoxane (MAO), all complexes proved productive catalysts for the polymerization of ethylene.
View Article and Find Full Text PDFResearch (Wash D C)
October 2019
Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
The 4,6-bis(arylimino)-1,2,3,7,8,9,10-heptahydrocyclohepta[]quinoline-iron(II) chlorides (aryl = 2,6-MeCH ; 2,6-EtCH ; 2,6--PrCH ; 2,4,6-MeCH ; and 2,6-Et-4-MeCH ) have been prepared in good yield by a straightforward one-pot reaction of 2,3,7,8,9,10-hexahydro-1H-cyclohepta[]quinoline-4,6-dione, FeCl·4HO, and the appropriate aniline in acetic acid. All ferrous complexes have been characterized by elemental analysis and FT-IR spectroscopy. In addition, the structure of has been determined by single crystal X-ray diffraction, which showed the iron center to adopt a distorted square pyramidal geometry with the saturated sections of the fused six- and seven-membered carbocycles to be -configured.
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