scholarly journals Synthesis of superabsorbent hydrogel based on starch copolymers and methods for their preparation

2021 ◽  
pp. 38-43
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Reaction Time ◽  
Ir Spectroscopy ◽  
Water Absorption ◽  
Superabsorbent Hydrogel ◽  
Synthesis Conditions ◽  
Molar Ratios ◽  
Degree Of Swelling ◽  
Molecular Ratios

The aim of this work is to synthesize and study a superabsorbent hydrogel based on starch copolymers. The optimal synthesis conditions have been determined and studies have been carried out on the effect of the molar ratios of the starting materials on the water absorption of the synthesized hydrogel. In the course of research, the optimum copolymerization temperature was 60 °C, and the reaction time was 3 hours. As a result of the study, a hydrogel was synthesized with a starch: acrylamide: bentonite ratio of 10 : 9 : 0.8, respectively. The resulting hydrogel was investigated by IR spectroscopy and differential thermal analysis. The influence of the molecular ratios of starch and acrylamide, as well as the concentration of the initiator, binder and bentonite, affecting the degree of swelling of the synthesized hydrogel, has been studied

Interlayer complexes of lanthanide-montmorillonites with amines

Clay Minerals ◽  
1982 ◽  
Vol 17 (2) ◽  
pp. 201-208 ◽  
Author(s):  
S. Bruque ◽  
L. Moreno-Real ◽  
T. Mozas ◽  
A. Rodriguez-Garcia
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Ir Spectroscopy ◽  
Amine Group ◽  
X Ray Diffraction ◽  
X Ray

AbstractSorption interlayer complexes of n-butylamine, sec-butylamine, iso-butylamine and diethylamine with homoionic Ln-montmorillonites (Ln = La, Sm, Gd, Er, Y) have been prepared. Compositions of the complexes are of the type: [Ln(butylamine)4]3+ and [Ln-(diethylamine)2]3+. The disposition of amine molecules surrounding the ion, the interaction between the amine group and the Ln3+ ion, and the strength of the ion-dipole bond have been studied by X-ray diffraction, IR spectroscopy and differential thermal analysis.

Hydrothermal growth and characterization of NaLa(WO4)2 crystals

1996 ◽  
Vol 11 (11) ◽  
pp. 2869-2875 ◽  
Author(s):  
K. Byrappa ◽  
Amita Jain
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Ir Spectroscopy ◽  
Hydrothermal Method ◽  
Crystal Morphology ◽  
Growth Parameters ◽  
Hydrothermal Growth ◽  
X Ray Diffraction ◽  
X Ray

The growth of NaLa(WO4)2 crystals has been carried out by the hydrothermal method at fairly low P-T conditions. The crystal morphology has been studied with respect to the growth parameters. The crystals obtained were characterized by various techniques such as x-ray diffraction (XRD), differential thermal analysis (DTA), and infrared (IR) spectroscopy.

Evaluation of antioxidants in lubricating oils by differential thermal analysis and IR spectroscopy

Wear ◽  
1982 ◽  
Vol 82 (1) ◽  
pp. 45-48 ◽  
Author(s):  
A.K. Biswas ◽  
B.D. Chattaraj ◽  
I. Suryanarayana ◽  
V.S.B. Rao
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Ir Spectroscopy ◽  
Lubricating Oils

The Synthesis and Performance of MgB2

2001 ◽  
Vol 689 ◽  
Author(s):  
R. L. Meng ◽  
B. Lorenz ◽  
Y. Y. Xue ◽  
D. Pham ◽  
J. Cmaidalka ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Melting Point ◽  
Transport Property ◽  
Chemical Reaction ◽  
Lattice Parameters ◽  
Synthesis Conditions ◽  
And Performance ◽  
Kinetics Of

ABSTRACTWe have studied the kinetics of the chemical reaction between Mg and B by differential thermal analysis. There are two exothermal peaks observed at 500 and 650 °C. We speculate that the first exothermal peak is mainly related to the chemical reaction between Mg and oxygen, forming MgO. The second exothermal peak, which coincides with the melting point of Mg, clearly indicates the chemical reaction between Mg and B. The effect of synthesis conditions and defects on the transport property of MgB2 has been investigated. A correlation between the microstrain, the lattice parameters, and the Mg concentration were observed and are discussed.

scholarly journals Preparation and characterization of carbamoylethyl hemicelluloses

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun-Li Ren ◽  
Feng Peng ◽  
Run-Cang Sun ◽  
Xun-Li Zhang
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Aqueous Solution ◽  
Differential Thermal Analysis ◽  
Main Chain ◽  
Carboxyl Groups ◽  
Molar Ratios ◽  
Ft Ir ◽  
C Nmr

AbstractThe reaction of hemicelluloses, isolated from wheat straw, with acrylamide in alkaline aqueous solution was investigated. The degree of substitution (DS, up to 0.65) of the products could be obtained by adjusting the molar ratios of reagent to xylose unit in hemicelluloses (1.0-10.0) and the molar ratios of catalyst to xylose unit in hemicelluloses (0.5-1.6). Changes in the structure of hemicelluloses were verified by FT-IR and 1H and 13C NMR spectroscopies. The results showed that carbamoylethyl groups surely were grafted onto the main chain of hemicelluloses. Moreover, it was also found that the saponification of carbamoylethyl groups to carboxyl groups occurred in alkaline medium. The behavior of modified hemicelluloses was monitored by means of thermo gravimetry (TG) and differential thermal analysis (TGA). It was found that the products had a lower thermal stability than the native hemicelluloses.

scholarly journals Synthesis and Properties of Bisthiadiazoles with Ethyl and Butyl Spacers

2020 ◽  
Vol 20 (4) ◽  
pp. 27-34
Author(s):  
Yu. V. Suvorova ◽  
E. A. Petukhova ◽  
E. A. Danilova ◽  
D. V. Tyurin
Keyword(s):  
Mass Spectrometry ◽  
Liquid Crystal ◽  
Reaction Time ◽  
Ir Spectroscopy ◽  
Biological Activities ◽  
Preparative Method ◽  
Synthesis Conditions ◽  
Crystal Properties ◽  
Macroheterocyclic Compounds ◽  
Selection Of

This article is devoted to a selection of the most effective preparative method for the synthesis of bis(5-amino-1,3,4-thiadiazole-2-yl)alkanes. These compounds are binuclear diamines consisting of symmetrical 1,3,4-thiadiazole fragments connected by alkyl spacers of various lengths. The structures of the obtained compounds were determined by IR spectroscopy, mass-spectrometry and elemental analysis. The possibility of using these molecules as precursors for the synthesis of macroheterocyclic compounds with expended coordination cavity consisting of six small cycles was demonstrated. Optimal synthesis conditions of bis(5-amino-1,3,4-thiadiazole-2-yl)ethane and bis(5-amino-1,3,4-thiadiazole-2-yl)butane were found by variation of reaction time and temperature. Virtual screening of the obtained compounds was carried out in order to predict antibacterial and biological activities as well as toxic properties of the targeted products. On the basis of the known literature data on polynuclear diamines, the exhibition of the liquid crystal properties of the synthesized molecules is supposed.

scholarly journals Synthesis of thiocol oligomer based on sodium tetrasulphide, epichlorhydrine and ammonium phosphate

2021 ◽  
pp. 32-37
Keyword(s):  
Differential Scanning Calorimetry ◽  
Reaction Time ◽  
Ir Spectroscopy ◽  
Ammonium Phosphate ◽  
Molar Ratio ◽  
Target Product ◽  
Optimal Conditions ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Main Component

The aim is to synthesize and study thiokol oligomer NEP-12 based on sodium tetrasulfide, epichlorohydrin and ammonium phosphate, which is intended for use as the main component of thiokol sealant. To achieve this goal, a thiokol oligomer based on sodium tetrasulfide, epichlorohydrin, and ammonium phosphate has been synthesized and investigated, and the optimal conditions for the synthesis of a thiokol oligomer have been determined. Research has been carried out on the influence of the molar ratios of the starting substances on the composition and physicochemical properties of the synthesized thiocol oligomer. 80 °C was taken as the optimum polycondensation temperature, the reaction time in this case is 1.5-2 hours, as a result, the yield of the target product reaches 94%. The thiokol oligomer with the best performance was obtained at a 1: 1: 1 molar ratio of sodium tetrasulfide, epichlorohydrin, and ammonium phosphate, respectively. Based on the results of IR spectroscopy and differential scanning calorimetry, a reaction for the formation of a thiokol oligomer is proposed.

Epoxy composition on the basis of triestertrisulfoimide saccharin-6-carboxylic acid

2020 ◽  
pp. 58-63
Author(s):  
E. T. Aslanova ◽  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Carboxylic Acid ◽  
Ir Spectroscopy ◽  
Curing Temperature ◽  
Curing Agent ◽  
Epoxide Resin ◽  
Alkyl Esters ◽  
Epoxy Composition ◽  
Composition And Structure

By the interaction of the previously synthesized 2-hydroxypropyl-1,3-bis-estersulfoimide of saccharin-6-carboxylyc acid with alkyl esters of sulfimide of the same acid triestertrisulfoimide saccharin-6-carboxylic acid has been obtained. The composition and structure of the synthesized compound has been confirmed by data of elemental analysis and IR-spectroscopy. The obtained product has been as a curing agent - plasticizer for industrial epoxide resin ED-20. It has been established that the triestertrisulfoimide of saccharin-6-carboxylic acidis the effective curing agent — plasticizer of epoxide resin ED-20. The curing prosses of composition was studied by a method of differential thermal analysis on derivatograph of system “Paulik-Paulik-Erdey”. It has been revealed according to the obtained data that the synthesized triestertrisulfoimide of saccharin-6-carboxylic acidis combined well with epoxide resin ED-20 but it is cured at hard temperature regime. It has been shown that in the introduction of accelerator UP 606/2 into epoxy composition the curing temperature of composition is decreased, but its thermal, physical -mechanical values are increased.

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