scholarly journals High Density Polyethylenes Bearing Isolated In-Chain Carbonyls

Author(s):  
Kyoko NOZAKI ◽  
Shan Tang ◽  
Falk William Seidel

Abstract Polyethylene materials are highly important polymers which are produced in the largest volume among all plastics. Due to the chemical inert property of saturated carbon-carbon bonds, the degradation of polyethylene is extremely challenging, which prevents them from efficient chemical recycling. Installing functional groups in the main chain of polyethylenes may facilitate the degradation and following chemical recycling of polyethylene materials. Here we report a highly selective approach for the synthesis of high-density polyethylenes bearing isolated in-chain carbonyls. Linear high-molecular weight polyethylene chains are synthesized via the palladium catalyzed copolymerization of ethylene with metal carbonyls. Different from traditional ethylene/CO copolymerization reactions, excellent non-alternating selectivity has been achieved. While the properties of polyethylene have been retained in the copolymer, faster degradation compared with that of polyethylene was observed upon UV light irradiation. The synthesized materials may therefore serve as more environmentally friendly alternative plastics than traditional polyethylene materials.

2018 ◽  
Vol 11 (05) ◽  
pp. 1850041 ◽  
Author(s):  
Anna Trojanowska ◽  
Valentina Marturano ◽  
Nuno A. G. Bandeira ◽  
Marta Giamberini ◽  
Bartosz Tylkowski

Photosensitive microcapsules are important targets for medical, pharmaceutical, agriculture, consumer goods and chemical companies. In this study, we report the development of UV-sensitive capsules containing vanillin as a model encapsulated active material. Polyamide microcapsule shells containing azobenzene moieties in the main chain of the polymer were fabricated by oil-in-water interfacial polymerization method. Triggered perfume release and morphological variations of the microcapsule shell during UV light irradiation were observed by means of high-performance liquid chromatography (HPLC) and optical microscopy.


2020 ◽  
Vol 75 (8) ◽  
pp. 727-732
Author(s):  
Chen Zhang ◽  
Jian-Qing Tao

AbstractA new Cu(II) metal-organic framework, [Cu(L)(OBA)·H2O]n (1) [H2OBA = 4,4′-oxybis(benzoic acid), L = 3,5-di(1H-benzimidazol-1-yl)pyridine] was hydrothermally synthesized and characterized through IR spectroscopy, elemental and thermal analysis and single-crystal X-ray diffraction. Complex 1 is a four-connected uni-nodal 2D net with a (44·62) topology which shows an emission centered at λ ∼393 nm upon excitation at λ = 245 nm. Moreover, complex 1 possesses high photocatalytic activities for the decomposition of Rhodamine B (RhB) under UV light irradiation.


Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1622
Author(s):  
Xiao-Pin Guo ◽  
Peng Zang ◽  
Yong-Mei Li ◽  
Dong-Su Bi

2-methylisoborneol (2-MIB) is a common taste and odor compound caused by off-flavor secondary metabolites, which represents one of the greatest challenges for drinking water utilities worldwide. A TiO2-coated activated carbon (TiO2/PAC) has been synthesized using the sol-gel method. A new TiO2/PAC photocatalyst has been successfully employed in photodegradation of 2-MIB under UV light irradiation. In addition, the combined results of XRD, SEM-EDX, FTIR and UV-Vis suggested that the nano-TiO2 had been successfully loaded on the surface of PAC. Experimental results of 2-MIB removal indicated that the adsorption capacities of PAC for 2-MIB were higher than that of TiO2/PAC. However, in the natural organic matter (NOM) bearing water, the removal efficiency of 2-MIB by TiO2/PAC and PAC were 97.8% and 65.4%, respectively, under UV light irradiation. Moreover, it was shown that the presence of NOMs had a distinct effect on the removal of MIB by TiO2/PAC and PAC. In addition, a simplified equivalent background compound (SEBC) model could not only be used to describe the competitive adsorption of MIB and NOM, but also represent the photocatalytic process. In comparison to other related studies, there are a few novel composite photocatalysts that could efficiently and rapidly remove MIB by the combination of adsorption and photocatalysis.


2021 ◽  
Vol 553 ◽  
pp. 149535
Author(s):  
Elisa Moretti ◽  
Elti Cattaruzza ◽  
Cristina Flora ◽  
Aldo Talon ◽  
Eugenio Casini ◽  
...  

Synthesis ◽  
2021 ◽  
Author(s):  
Fabiane Gritzenco ◽  
Jean Carlo Kazmierczak ◽  
Thiago Anjos ◽  
Adriane Sperança ◽  
Maura Luise Bruckchem Peixoto ◽  
...  

This manuscript portrays the CuI-catalyzed Csp-chalcogen bond formation through cross-coupling reactions of propynyl esters and diorganyl dichalcogenides by using DMSO as solvent, at room temperature, under base-free and open-to-air atmosphere. Generally, the reactions have proceeded very smoothly, being tolerant to range of substituents present in both substrates, affording the novel 3-(organochalcogenyl)prop-2-yn-1-yl esters in moderate to good yields. Noteworthy, the 3-(butylselanyl)prop-2-yn-1-yl benzoate proved to be useful as synthetic precursor in palladium-catalyzed Suzuki and Sonogashira type cross-coupling reactions by replacing the carbon-chalcogen bond by new carbon-carbon bonds. Moreover, the 3-(phenylselanyl)prop-2-yn-1-yl benzoate has shown promising in vitro activity against glioblastoma cancer cells.


2021 ◽  
Author(s):  
Yumei Mao ◽  
Xuehua Dong ◽  
Yuandan Deng ◽  
Jing Li ◽  
Ling Huang ◽  
...  

Two new zinc phosphites were prepared using the amino acid alanine as structure-directing agent. They have tubular and ladder-like structures exhibiting blue fluorescence upon UV light irradiation. Notably, the tubular...


1996 ◽  
Vol 54 (4) ◽  
pp. 331-337 ◽  
Author(s):  
M.Perla Colombini ◽  
Fabio Di Francesco ◽  
Roger Fuoco

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