Difluoromethyl Nitrile Oxide (CF2HCNO): A Neglected Chemical Reagent

2017 ◽  
Vol 2017 (27) ◽  
pp. 3935-3940 ◽  
Author(s):  
Andrii Khutorianskyi ◽  
Bohdan Chalyk ◽  
Petro Borysko ◽  
Anna Kondratiuk ◽  
Pavel K. Mykhailiuk
Keyword(s):  
Nitrile Oxide ◽  
Chemical Reagent

Deinking of recycled paper by coupling of the enzyme endo-β-1,4-D-glucanasa and the cellulose, and by using a laboratory flotation column

MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2669-2678
Author(s):  
Jeovani González P. ◽  
Ramiro Escudero G
Keyword(s):  
Amino Acids ◽  
Sodium Hydroxide ◽  
Paper Industry ◽  
Computational Simulation ◽  
Cellulose Fibers ◽  
Residual Water ◽  
Chemical Reagent ◽  
Recycled Paper ◽  
Flotation Column ◽  
Hydrolysis Of

AbstractDeinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.

Scientific and technological aspects and prospects for application of cryogenic drilling technology

2020 ◽  
pp. 54-62
Author(s):  
A. B. Tulubaev ◽  
E. V. Panikarovskii
Keyword(s):  
Low Temperatures ◽  
Western Siberia ◽  
Wellbore Stability ◽  
Drilling Mud ◽  
Chemical Reagent ◽  
Production Chain ◽  
Foreign Experience ◽  
Permafrost Rocks ◽  
The North ◽  
Drilling Technology

In the article, we analyze types of drilling mud, which are used to drilling intervals of permafrost rocks; the importance of wellbore stability is noted. Wedescribethemain technologies, which have been being applied in the north of Western Siberia; these technologies are aimed at minimizing the loss wellbore stability due to violation of the temperature conditions in the well. We also analyze hydrocarbon systems, taking into account foreign experience, which is based on prospecting and exploratory drilling of ice deposits in Greenland and Antarctica. The article draws your attention to using synthetic fluids, monoesters and chladones. The difficulties of the existing technology and the disadvantages of the hydrocarbon systems are highlighted. We propose to apply a new cryogenic drilling technology, which consists in the use of synthetic fluorine-containing agents as flushing fluid at low temperatures. The text gives valuable information on composition of the proposed flushing fluid and the prospects of using the technology to prevent complications. Much attention is given to issue of manufacturing the main chemical reagent with the reduction of the generalized production chain of its production from the starting material, it is fluorspar.

π-Facial Selectivity in 1,3-Dipolar Cycloaddition Reactions of α-Methylidene-γ-lactone Substituted by 4-Methyl-2,6,7-trioxabicyclo[2.2.2]octan-1-yl Group in γ-Position

2002 ◽  
Vol 67 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Petr Melša ◽  
Ctibor Mazal
Keyword(s):  
Double Bond ◽  
Carboxylic Acid ◽  
Nitrile Oxide ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Enantiomerically Pure ◽  
Nitrile Imine ◽  
Facial Selectivity ◽  
Excellent Selectivity

Diastereoselectivity of 1,3-dipolar cycloaddition reactions of benzyl azide, diazomethane, a nitrile oxide and a nitrile imine to α-methylidene-γ-lactone dipolarophile was effectively controlled by a bulky γ-substituent, 4-methyl-2,6,7-trioxabicyclo[2.2.2]octan-1-yl in γ-position of the dipolarophile. The dipoles added from the less hindered face of the double bond with an excellent selectivity. Enantiomerically pure dipolarophile was prepared from the easily available (S)-5-oxotetrahydrohydrofuran-2-carboxylic acid.

scholarly journals Numerical Analysis of the Bond Strength between Two Methacrylic Polymers by Surface Modification

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3927
Author(s):  
Joanna Taczała ◽  
Katarzyna Rak ◽  
Jacek Sawicki ◽  
Michał Krasowski
Keyword(s):  
Numerical Analysis ◽  
Bond Strength ◽  
Angular Position ◽  
Fem Analysis ◽  
Groove Depth ◽  
Chemical Reagent ◽  
Shear Process ◽  
3D Geometry ◽  
The Right ◽  
Artificial Teeth

The creation of acrylic dentures involves many stages. One of them is to prepare the surfaces of artificial teeth for connection with the denture plates. The teeth could be rubbed with a chemical reagent, the surface could be developed, or retention hooks could be created. Preparation of the surface is used to improve the bond between the teeth and the plate. Choosing the right combination affects the length of denture use. This work focuses on a numerical analysis of grooving. The purpose of this article is to select the shape and size of the grooves that would most affect the quality of the bond strength. Two types of grooves in different dimensional configurations were analyzed. The variables were groove depth and width, and the distance between the grooves. Finally, 24 configurations were obtained. Models were analyzed in terms of their angular position to the loading force. Finite element method (FEM) analysis was performed on the 3D geometry created, which consisted of two polymer bodies under the shear process. The smallest values of the stresses and strains were characterized by a sample with parallel grooves with the grooving dimensions width 0.20 mm, thickness 0.10 mm, and distance between the grooves 5.00 mm, placed at an angle of 90°. The best dimensions from the parallel (III) and cross (#) grooves were compared experimentally. Specimens with grooving III were not damaged in the shear test. The research shows that the shape of the groove affects the distribution of stresses and strains. Combining the selected method with an adequately selected chemical reagent can significantly increase the strength of the connection.

Hypervalent-Iodine Mediated One-Pot Synthesis of Isoxazolines and Isoxazoles bearing Difluoromethyl Phosphonate Moiety

2021 ◽  
Author(s):  
Romana Pajkert ◽  
Henryk Koroniak ◽  
Pawel Kafarski ◽  
Gerd Volker Roeschenthaler
Keyword(s):  
Nitrile Oxide ◽  
Dipolar Cycloaddition ◽  
Hypervalent Iodine ◽  
One Pot ◽  
One Pot Synthesis

A one-pot, regioselective 1,3-dipolar cycloaddition of in situ generated (diethoxyphosphoryl)difluoromethyl nitrile oxide toward selected alkenes and alkynes is reported. This protocol enables facile access to 3,5-disubstituted isoxazolines and isoxazoles bearing...

A Novel Nitrile Oxide Precursor; 2-Methyl-4-nitro-5(2H)-isoxazolone

Heterocycles ◽  
1992 ◽  
Vol 34 (8) ◽  
pp. 1511 ◽  
Author(s):  
Masahiro Ariga ◽  
Suguru Higashida ◽  
Hiroko Nakashima ◽  
Yasuo Tohda ◽  
Keita Tani ◽  
...  
Keyword(s):  
Nitrile Oxide ◽  
Oxide Precursor

Chiral Lewis Acid Catalysis in Nitrile Oxide Cycloadditions

2004 ◽  
Vol 126 (17) ◽  
pp. 5366-5367 ◽  
Author(s):  
Mukund P. Sibi ◽  
Kennosuke Itoh ◽  
Craig P. Jasperse
Keyword(s):  
Lewis Acid ◽  
Acid Catalysis ◽  
Nitrile Oxide ◽  
Lewis Acid Catalysis ◽  
Chiral Lewis Acid
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