Preparation and thermal stability of carboxymethyl starch/quaternary ammonium salts complexes

2011 ◽  
Vol 83 (4) ◽  
pp. 1680-1689 ◽  
Author(s):  
Vittoria Balsamo ◽  
Francisco López-Carrasquero ◽  
Estrella Laredo ◽  
Katherine Conto ◽  
Jesús Contreras ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Carboxymethyl Starch ◽  
Thermal Stability Of

Viscosity of Gelatin Solution Containing Cationic Crosslinker

2013 ◽  
Vol 750-752 ◽  
pp. 1660-1663
Author(s):  
Xiang Jian Meng ◽  
Yue Zhi Cui ◽  
Cong De Qiao ◽  
Tian Duo Li ◽  
Jing Xu
Keyword(s):  
Thermal Stability ◽  
Organic Compounds ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Gelatin Solution ◽  
Ionic Bond ◽  
Organic Salts ◽  
Thermal Stability Of

Gelatin, as an amphoteric polyelectrolyte, can combine with cationic or anionic organic compounds by ionic bond. In this work, two binary quaternary ammonium salts have been prepared from 1,2-ethanediamine and 1,4-butanediamine. The viscosity of aqueous gelatin solution containing these two organic salts is studied systematically, which verifies the occurrence of the crosslinking between the gelatin and the binary quaternary ammonium salts. This crosslinking improves the thermal stability of the dried gelatin.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

scholarly journals Degradation Kinetics and Solvent Effects of Various Long-Chain Quaternary Ammonium Salts

2021 ◽  
Author(s):  
Roel Kleijwegt ◽  
Wyatt Winkenwerder ◽  
Wim Baan ◽  
John van der Schaaf
Keyword(s):  
Thermal Stability ◽  
Solvent Effects ◽  
Quaternary Ammonium ◽  
Degradation Kinetics ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Polar Solvents ◽  
Kinetics Of ◽  
Thermal Stability Of ◽  
Long Chain

<div>Surfactants such as quaternary ammonium salts (QAS) have been in increasing demand, for emerging new applications. Recent attempts at process intensification of</div><div>their production, have disclosed the need for a better understanding of QAS thermal stability. This work aims to determine degradation kinetics of various QASs, and the</div><div>associated solvent effects. Degradation kinetics of four methyl carbonate QASs were determined in various</div><div>polar solvents in stainless steel batch autoclaves. <sup>1</sup>H NMR spectrometry was employed for online analysis of the reaction mixtures. The kinetic parameters were then used</div><div>to compare the thermal stability of the four compounds in the polar solvents. Water showed not degradation, and methanol (MeOH) was the solvent that provided the</div><div>second-best stability. Water-MeOH mixtures may provide an overall optimum. More, and longer long-chain substituents increased the degradation rate. Thermogravimetric Analysis was used to obtain the thermal stability in a solid-</div><div>state, i.e. solventless environment. Isoconversional analysis showed that no reliable kinetic parameters could be determined. Nevertheless, the data did allow for a compar-</div><div>ison of the thermal stability of 14 different QASs. Furthermore, the relative instability of the compounds in solid-state demonstrated the challenges of solventless QAS production.</div>

scholarly journals Degradation Kinetics and Solvent Effects of Various Long-Chain Quaternary Ammonium Salts

2021 ◽  
Author(s):  
Roel Kleijwegt ◽  
Wyatt Winkenwerder ◽  
Wim Baan ◽  
John van der Schaaf
Keyword(s):  
Thermal Stability ◽  
Solvent Effects ◽  
Quaternary Ammonium ◽  
Degradation Kinetics ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Polar Solvents ◽  
Kinetics Of ◽  
Thermal Stability Of ◽  
Long Chain

<div>Surfactants such as quaternary ammonium salts (QAS) have been in increasing demand, for emerging new applications. Recent attempts at process intensification of</div><div>their production, have disclosed the need for a better understanding of QAS thermal stability. This work aims to determine degradation kinetics of various QASs, and the</div><div>associated solvent effects. Degradation kinetics of four methyl carbonate QASs were determined in various</div><div>polar solvents in stainless steel batch autoclaves. <sup>1</sup>H NMR spectrometry was employed for online analysis of the reaction mixtures. The kinetic parameters were then used</div><div>to compare the thermal stability of the four compounds in the polar solvents. Water showed not degradation, and methanol (MeOH) was the solvent that provided the</div><div>second-best stability. Water-MeOH mixtures may provide an overall optimum. More, and longer long-chain substituents increased the degradation rate. Thermogravimetric Analysis was used to obtain the thermal stability in a solid-</div><div>state, i.e. solventless environment. Isoconversional analysis showed that no reliable kinetic parameters could be determined. Nevertheless, the data did allow for a compar-</div><div>ison of the thermal stability of 14 different QASs. Furthermore, the relative instability of the compounds in solid-state demonstrated the challenges of solventless QAS production.</div>

Synthesis and stability of 1-aminoalkylphosphonic acid quaternary ammonium salts

2021 ◽  
Author(s):  
Tomasz K. Olszewski ◽  
Anna Brol
Keyword(s):  
Phosphonic Acid ◽  
Quaternary Ammonium ◽  
Alkylating Agent ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Aminoalkylphosphonic Acid

An effective protocol for quaternization of simple 1-aminoalkylphosphonic acids under basic conditions and using Me2SO4 as convenient alkylating agent is reported. In the course of reaction phosphonic acid quaternary ammonium...

scholarly journals Green Accelerated Synthesis, Antimicrobial Activity and Seed Germination Test of Quaternary Ammonium Salts of 1,2-bis(4-pyridyl)ethane

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2424 ◽  
Author(s):  
Tăbăcaru ◽  
Botezatu ◽  
Horincar ◽  
Furdui ◽  
Dinică
Keyword(s):  
Escherichia Coli ◽  
Triticum Aestivum ◽  
Seed Germination ◽  
Quaternary Ammonium ◽  
Pathogenic Bacteria ◽  
Classical Method ◽  
Triticum Aestivum L ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Radicle Growth

A family of fifteen quaternary ammonium salts (QAs), bearing the 1,2-bis(4-pyridyl)ethane core, were obtained using for the first time two different green methods, such as microwave (MW) and ultrasounds (US) irradiation, with very good yields and in much shorter times compared to the classical method, and an assay on their antimicrobial action against Escherichia coli (E. coli) was carried out. While 12 to 24 hours were required for complete alkylation of 1,2-bis(4-pyridyl)ethane by reactive halogenated derivatives in anhydrous solvent under reflux conditions, MW and US irradiation reduced the reaction time and the desired products were achieved in a few min. One of the aims of this study was to evaluate the antibacterial potential of the synthesized QAs against pathogenic bacteria, along with their impact on germination activity of wheat seeds (Triticum aestivum L.). The antibacterial activity of the QAs against Escherichia coli was explored by determining the minimum inhibitory concentration (MIC). The MIC values varied from 0.312 to 2.5 mg/mL, highlighting the lowest values attained for the derivatives containing methoxy, chlorine and benzofurane functional groups. The viability of aerobic bacteria was determined with the Tetrazolium/Formazan Test, a method that was found to be the best alternative approach with respect to the difuzimetric method. Seeds of Triticum aestivum L. were used for the evaluation of the germination indicators, such as seed germination (SG), the relative seed germination (RSG), the relative radicle growth (RRG), and the seed germination index (GI). The toxicity studies of QAs 1, 4 and 7, at two different concentrations, showed no inhibitory effect on seed germination.

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