Thermal stability of quaternary ammonium hexafluorophosphates and halides

Zhuravlev, O. E.; Nikol’skii, V. M.; Voronchikhina, L. I.

doi:10.1134/s1070427213060062

“…The average bond energies of C–O (358 kJ/mol) are higher than the average bond energies of C–N (305 kJ/mol), and the long alkyl chains of DDHAC were broken above 165°C. The quaternary ammonium cation was detached from PGDs that were decomposed to tertiary amine groups, as indicated in Figure . The most important result was that thermal stability up to 155°C of PEAA grafted with DDHAC significantly increased in contrast to unmodified PEAA.…”

Section: Resultsmentioning

confidence: 99%

Preparation of Poly(ethylene‐co‐acrylic acid) Grafted with Aliphatic Quaternary Ammonium Salts as Antibacterial Polymers

Noh

¹

,

Yu

²

,

Ko

³

et al. 2017

Bulletin Korean Chem Soc

6

0

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To improve the antibacterial performance of poly(ethylene-co-acrylic acid) (PEAA) copolymer, aliphatic quaternary ammonium salts (QASs) was grafted into PEAA copolymers via a Steglich esterification reaction using N,N 0 -dicyclohexylcarbodiimide (DCC) as a dehydrating agent. The polymers were synthesized using dodecyl dimethyl hydroxyethyl ammonium chloride (DDHAC), which was prepared by quaternization of dimethylethanolamine (DMEA) with 1-chlorododecane. These polymers effectively inhibited the growth of microorganisms due to their hydrophobic chains, which were bound to PEAA copolymers. The obtained PEAA-g-DDHAC (PGD) was investigated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance ( 1 H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and antibacterial tests. The results showed that the antibacterial effects of PGDs were significantly improved by alkyl grafting, and this improvement depended on reaction temperature. The highest antibacterial activity was observed for polymers synthesized at 135 C against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Their decomposition rate was accelerated as the temperature increased above 165 C because of the thermal decomposition of DDHAC.

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“…1. However, at most reaction conditions, it is presumed to have a less significant contribution to the degradation 4,6 .…”

Section: Degradation Mechanismsmentioning

confidence: 99%

“…These increasingly demanding appliances require highly stable compounds. Recent studies have therefore already focused on the elucidation of their thermal and alkaline stability 4,6 .…”

Section: Introductionmentioning

confidence: 99%

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

Kleijwegt

¹

,

Winkenwerder²,

Baan³

et al. 2021

Preprint

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<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>

show abstract

“…1. However, at most reaction conditions, it is presumed to have a less significant contribution to the degradation 4,6 .…”

Section: Degradation Mechanismsmentioning

confidence: 99%

“…These increasingly demanding appliances require highly stable compounds. Recent studies have therefore already focused on the elucidation of their thermal and alkaline stability 4,6 .…”

Section: Introductionmentioning

confidence: 99%

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

Kleijwegt

¹

,

Winkenwerder

²

,

Baan³

et al. 2021

Preprint

View full text Add to dashboard Cite

<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>

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Thermal stability of quaternary ammonium hexafluorophosphates and halides

Cited by 23 publications

References 11 publications

Preparation of Poly(ethylene‐co‐acrylic acid) Grafted with Aliphatic Quaternary Ammonium Salts as Antibacterial Polymers

Preparation of Poly(ethylene‐co‐acrylic acid) Grafted with Aliphatic Quaternary Ammonium Salts as Antibacterial Polymers

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

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

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