- Ethoxylated trimethylolpropane core hyperbranched polymer taking dithiocarboxylate as side group and end group and application of chelating metal
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The invention provides an ethoxylated trimethylolpropane core hyperbranched polymer taking dithiocarboxylate as a side group and an end group and a preparation method and application of the ethoxylated trimethylolpropane core hyperbranched polymer as a heavy metal chelating agent, and relates to the technical field of chemical engineering and environmental protection. The chemical formula of the ethoxylated trimethylolpropane core hyperbranched polymer taking dithiocarboxylate as a side group and an end group is CH3CH2C [CH2OCH2CH2OCOCH2CH2CH2N (CSSM) CH2CH2NHCSSM] 3, wherein M is Na, Kor NH4. The hyperbranched polymer provided by the invention is simple in preparation method, easily available in raw materials and easy to industrialize. The hyperbranched polymer can be used as aheavy metal chelating agent, the special three-dimensional space structure of the hyperbranched polymer can be alternately chelated with heavy metals to form a three-dimensional super-macromolecular combination with low solubility and strong stability, and wastewater and wastes containing heavy metals can be effectively treated.
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Paragraph 044-0048
(2020/05/14)
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- Compound heavy metal chelating agent containing dithiocarboxylate functionalized ethoxylated pentaerythritol core hyperbranched polymer
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A compound heavy metal chelating agent, which relates to the field of chemical and environmental protection technology, includes dithiocarboxylate functionalized ethoxylated pentaerythritol core hyperbranched polymer and alkylene diamine-N,N′-sodium bisdithiocarboxylate with a molar ratio in a range of 1:1.0 to 1:10.0. The two different structural types of components have the synergistic positive effect. While chelating heavy metals, the compound heavy metal chelating agent alternately combine with heavy metals to form insoluble chelating super-molecular deposits, which has both chelation and flocculation functions. The compound heavy metal chelating agent provided by the present invention is able to reach the standard for treating heavy metal wastewater, and especially low concentration heavy metal wastewater. It has a wide adaptability range, and does not need to add coagulant. Moreover, it is simple in preparation method, easily available for raw materials, low in cost, and easy to be industrialized.
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Paragraph 0033-0035
(2020/12/13)
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- Mechanisms of acid decomposition of dithiocarbamates. 2. Efficiency of the intramolecular general acid catalysis
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The acid decomposition of ethylenebis(dithiocarbamate) (EbisDTC) and glycinedithiocarboxylate (glyDTC) was studied in water at 25 °C in the range of rio -5 to pH 5. The acid dissociation constants of all species involved were calculated from LFER and from the pH-rate profiles. According to the pK(a) of the parent amine of the reactive species, both compounds decompose through the dithiocarbamate anion and a zwitterion intermediate. The intermolecular N-protonation rate constant of the carboxylic conjugate acid of glyDTC anion is 12.6 M-1 s-1, slower than the C-N breakdown. This species also cleaves through an intramolecular general acid-catalyzed mechanism where the rate constant for the N-protonation is (7.1 ± 4.2) x 103 s-1 and the efficiency of the proton-transfer step as measured by the effective molarity is (5.6 ± 3.3) x 102 M. The acid decomposition of the dithiocarbamic conjugate acid of EbisDTC anion proceeds through a fast N- protonation and a slower C-N breakdown. The intramolecular general acid catalysis rate constant is (8.2 ± 2.8) x 106 s-1, but the efficiency of this fast proton transfer is only (14.3 ± 4.9) M. The intramolecular general acid catalysis of the free acid forms of the carboxylic and dithiocarbamic groups is unfavorable for about 4 kcal mol-1 with respect to the protonation of the external hydron, and consequently, no external buffer catalysis is expected to be observed for dithiocarbamates that decompose through a zwitterion intermediate. The difference between the pK(b) of the proton acceptor and the pK(a) of the donor follows the order of the proton efficiency. Estimation of the strength of the hydrogen bonding in the reagent and product supports the assumption that a thermodynamically favorable change of hydrogen bonding from reagent to product increases the efficiency of proton transfer.
- Humeres, Eduardo,Debacher, Nito A.,Sierra, M. Marta De S.
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p. 1807 - 1813
(2007/10/03)
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- Fungicidal composition for seed dressing
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The present invention relates to a fungicidal composition intended for the protection of the multiplication products of cultivated plants, containing: (a) 2-(4-chlorobenzylidene)-5,5-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-1-cyclopentanol; (b) one or more fungicides suitable for the protection of the said multiplication products, optionally one or more insecticides, (c), an agriculturally acceptable inert vehicle and an agriculturally acceptable surfactant. The invention also relates to a method for protecting the multiplication products of plants against fungal diseases using these compositions.
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- Fungicidal compositions employing synergistic mixtures of phenylacetamide derivatives and Zineb or Mancozeb
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Synergistic mixtures of fungicidal N-(2,6-dimethyl-phenyl)-N-(1-methoxycarbonyl-ethyl)-phenylacetamide with other selected fungicides which are ethylene-bis-dithiocarbamates, N-trichloromethylthio-imides or copper oxychloride are disclosed as are compositions comprising the synergistic mixtures. Said mixtures and compositions are effective in controlling fungi infections of useful plants.
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