scholarly journals Catalyses by Polymer Complexes. VI. Catalysis of Proton Abstraction from α-Ketols by Hydroxamate Ions Bound to Polymer Micelles

1977 ◽  
Vol 9 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Seiji Shinkai ◽  
Toyoki Kunitake
Keyword(s):  
Polymer Micelles ◽  
Polymer Complexes ◽  
Proton Abstraction ◽  
Hydroxamate Ions

THE ECONOMY OF WATER RESOURCES WITH THE USE OF POLYMER COMPLEXES IN IRRIGATION OF A COTTON

2018 ◽  
pp. 8-12
Author(s):  
M. Khamidov ◽  
B. Suvanov ◽  
K. Khamroev
Keyword(s):  
Water Resources ◽  
Moisture Capacity ◽  
Polymer Complexes ◽  
Maturation Phase ◽  
Flowering Phase ◽  
Fruit Cultivation ◽  
Growth Development ◽  
Control Variant ◽  
Maximum Field ◽  
Alluvial Meadow

The article deals with the use of polymer complexes in alluvial-meadow soils under the pre-determined humidity of 70-80-65% of the maximum field moisture capacity, in the second option with the 1-2-1 scheme in the Bukhara oasis. During the seedling and flowering phase, one irrigation irrigation norm was performed at 734 m3/ha; during the blooming and fruit cultivation phase, three irrigation operations were performed with irrigation norms of 631-644 m3/ha, one irrigation with a watering rate of 865 m3/ha was performed during the maturation phase. The irrigation norm was 2874 m3/ha or, relative to the control variant, by 1754 m3/ha less, which allowed saving manual water, as well as the results of the conducted experiments and their impact on cotton growth, development and yield.

ESTIMATING THE STABILITY OF METAL–LIGAND BONDING IN CARBOXYL-CONTAINING POLYMER COMPLEXES BY IR SPECTROSCOPY

2020 ◽  
Vol 61 (12) ◽  
pp. 1876-1887
Author(s):  
T. V. Berestova ◽  
K. N. Nosenko ◽  
O. V. Lusina ◽  
L. G. Kuzina ◽  
E. I. Kulish ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Polymer Complexes ◽  
The Stability ◽  
Metal Ligand

Mobility op polymer micelles

1995 ◽  
Vol 90 (1) ◽  
pp. 237-249
Author(s):  
Elizaveta V. Anufrieva ◽  
Raisa A. Gromova ◽  
Vanda B. Lushchik ◽  
Tatyana N. Nekrasova ◽  
Mark G. Krakoviak
Keyword(s):  
Polymer Micelles

scholarly journals Effect of Molecular Architecture on Associating Behavior of Star-Like Amphiphilic Polymers Consisting of Plural Poly(ethylene oxide) and One Alkyl Chain

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 460
Author(s):  
Daisuke Kugimoto ◽  
Aoi Taniguchi ◽  
Masaki Kinoshita ◽  
Isamu Akiba
Keyword(s):  
Ethylene Oxide ◽  
Average Molecular Weight ◽  
Amphiphilic Polymers ◽  
Hydrophobic Core ◽  
Molecular Architecture ◽  
Polymer Micelles ◽  
The Core ◽  
X Ray Scattering ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Associating behavior of star-like amphiphilic polymers consisting of two or three poly(ethylene oxide) (PEO) chains and one stearyl chain (C18) was investigated. Although the aggregation number (Nagg) of linear analogue of amphiphilic polymers monotonically decreased with increasing number-average molecular weight of PEO (Mn,PEO), the Nagg of micelles of star-like amphiphilic polymers with Mn,PEO = 550 g/mol was smaller than that with Mn,PEO = 750 g/mol, whereas that with Mn,PEO ≥ 750 g/mol showed general Mn,PEO dependence. Small-angle X-ray scattering analyses revealed that the occupied area of one PEO chain on the interface between hydrophobic core and corona layer in the micelles of star-like polymers was much narrower than that in the linear amphiphilic polymers. This result indica ted the PEO chains of star-like polymers partially took unfavorable conformation near the core–corona interface in polymer micelles. The effect of local conformation of PEO chains near the interface on the associating behavior became significant as Mn,PEO decreased. Therefore, in polymer micelles of star-like amphiphilic polymers containing PEO with Mn,PEO = 550 g/mol, the enlargement of occupied area of PEO on the core–corona interface should be caused to avoid the formation of unfavorable conformations of partial PEO chains, resulting in a decrease in Naggs.

scholarly journals Kinetics and Mechanism of the Change of the 4-Nitrobenzylthio-System into 4,4′-Diformylazoxybenzene in Alkaline Dioxane-Water Media

1985 ◽  
Vol 40 (11) ◽  
pp. 1128-1132
Author(s):  
Y. Riad ◽  
Adel N. Asaad ◽  
G.-A. S. Gohar ◽  
A. A. Abdallah
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Rate Constants ◽  
Main Product ◽  
Reaction Medium ◽  
Aqueous Dioxane ◽  
Proton Abstraction ◽  
First Order ◽  
Water Media ◽  
Different Temperatures

Sodium hydroxide reacts with α -(4-nitrobenzylthio)-acetic acid in aqueous-dioxane media to give 4,4'-diformylazoxybenzene as the main product besides 4,4'-dicarboxyazoxybenzene and a nitrone acid. This reaction was kinetically studied in presence of excess of alkali in different dioxane-water media at different temperatures. It started by a fast reversible a-proton abstraction step followed by two consecutive irreversible first-order steps forming two intermediates (α -hydroxy, 4-nitrosobenzylthio)-acetic acid and 4-nitrosobenzaldehyde. The latter underwent a Cannizzaro's reaction, the products of which changed in the reaction medium into 4,4'-diformylazoxybenzene and 4,4'-dicarboxyazoxybenzene. The rate constants and the thermodynamic parameters of the two consecutive steps were calculated and discussed. A mechanism was put forward for the formation of the nitrone acid.Other six 4-nitrobenzyl, aryl sulphides were qualitatively studied and they gave mainly 4,4'-diformylazoxybenzene beside 4,4'-dicarboxyazoxybenzene or its corresponding azo acid.

The Mechanism of Sugar C−H Bond Oxidation by a Flavoprotein Oxidase Occurs by a Hydride Transfer Before Proton Abstraction

2019 ◽  
Vol 25 (17) ◽  
pp. 4460-4471 ◽  
Author(s):  
Thanyaporn Wongnate ◽  
Panida Surawatanawong ◽  
Litavadee Chuaboon ◽  
Narin Lawan ◽  
Pimchai Chaiyen
Keyword(s):  
Hydride Transfer ◽  
Proton Abstraction
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