“…This assignment is summarized on the thermogram in Figure . The ability for potassium malonate to make a dihydrate has been previously documented in the literature, and thermogravimetric experiments on potassium malonate K 2 C 3 H 2 O 4 and its hydrates have indicated that monodecarboxylation occurs around 400 °C as hypothesized here for polymer 2 . − Both elemental analysis and TGA experiment once again confirm the structure previously assigned for 2 . 3 Thermogravimetric curve for polymer 2 (heating rate: 10 K min -1 , N 2 ).…”
Section: Resultssupporting
confidence: 81%
“…It can be hypothesized that the first weight loss is due to the progressive release of water molecules contained in the sample, which includes both physically adsorbed and chemically bound water. Malonate salts like most inorganic compounds are very hygroscopic and can provide hydrates of various stoichiometries. − Assuming that the macromolecule is entirely dehydrated after the first 10% weight loss, one can calculate that the water content in the starting materials amounts to 1.27 water molecules per malonate repeating unit in the polymer. C−H−K elemental analysis on the other hand indicates that the total amount of water in the polymer sample amounts to 2.33 water molecules for each CH 2 CH 2 C(COOK) 2 unit (based on a very good fit between theoretical composition for (CH 2 CH 2 C(COOK) 2 ·2.33 H 2 O) n (C = 24.18%, H = 3.52%, K = 31.49%) and the measured composition (C = 24.21%, H = 2.64%, K = 31.70%)).…”
Section: Resultsmentioning
confidence: 99%
“…(The carboxylate ion is not a good electron-withdrawing group.) This higher stability is reflected in the very high temperature (>350 °C) required to decarboxylate malonate ions (see also the TGA in Figure ). − The absence of decarboxylated units in the structure of polymer 2 suggests that decarboxylation of the hemihydrolyzed malonate is also slow in a refluxing water−dioxane mixture. It must be mentioned that malonate-containing polymer 4 was also reported recently to be reluctant to decarboxylate, in agreement with our own findings in this study …”
The potassium salt of poly(trimethylene-1,1-dicarboxylic acid), the first member of a new polyelectrolyte family where the carbon backbone is substituted on every third carbon by two carboxylate anions, was obtained by hydrolysis of a monodisperse di-n-propyl ester polymer (CH 2CH2C(COOnPr)2)n. This precursor can be synthesized by anionic ring-opening polymerization of di-n-propylcyclopropane-1,1-dicarboxylate using a polymerization procedure already proved to be living for a similar cyclopropyl monomer. The polyelectrolyte potassium salt was fully characterized by solid-state 13 C NMR, FT-IR, elemental analysis, and thermogravimetry (TGA), providing clear evidence for a very selective and clean hydrolysis. The malonate ion substructure on the polymer is very stable and does not decompose below 350°C. No procedure could be identified to cleanly decarboxylate the polymer to the monosubstituted system. The polymer is very insoluble in water unless high concentrations of potassium hydroxide are used (>1 mol L -1 ), a behavior consistent with the very high symmetry of the polymer and its high tendency to crystallize.
“…This assignment is summarized on the thermogram in Figure . The ability for potassium malonate to make a dihydrate has been previously documented in the literature, and thermogravimetric experiments on potassium malonate K 2 C 3 H 2 O 4 and its hydrates have indicated that monodecarboxylation occurs around 400 °C as hypothesized here for polymer 2 . − Both elemental analysis and TGA experiment once again confirm the structure previously assigned for 2 . 3 Thermogravimetric curve for polymer 2 (heating rate: 10 K min -1 , N 2 ).…”
Section: Resultssupporting
confidence: 81%
“…It can be hypothesized that the first weight loss is due to the progressive release of water molecules contained in the sample, which includes both physically adsorbed and chemically bound water. Malonate salts like most inorganic compounds are very hygroscopic and can provide hydrates of various stoichiometries. − Assuming that the macromolecule is entirely dehydrated after the first 10% weight loss, one can calculate that the water content in the starting materials amounts to 1.27 water molecules per malonate repeating unit in the polymer. C−H−K elemental analysis on the other hand indicates that the total amount of water in the polymer sample amounts to 2.33 water molecules for each CH 2 CH 2 C(COOK) 2 unit (based on a very good fit between theoretical composition for (CH 2 CH 2 C(COOK) 2 ·2.33 H 2 O) n (C = 24.18%, H = 3.52%, K = 31.49%) and the measured composition (C = 24.21%, H = 2.64%, K = 31.70%)).…”
Section: Resultsmentioning
confidence: 99%
“…(The carboxylate ion is not a good electron-withdrawing group.) This higher stability is reflected in the very high temperature (>350 °C) required to decarboxylate malonate ions (see also the TGA in Figure ). − The absence of decarboxylated units in the structure of polymer 2 suggests that decarboxylation of the hemihydrolyzed malonate is also slow in a refluxing water−dioxane mixture. It must be mentioned that malonate-containing polymer 4 was also reported recently to be reluctant to decarboxylate, in agreement with our own findings in this study …”
The potassium salt of poly(trimethylene-1,1-dicarboxylic acid), the first member of a new polyelectrolyte family where the carbon backbone is substituted on every third carbon by two carboxylate anions, was obtained by hydrolysis of a monodisperse di-n-propyl ester polymer (CH 2CH2C(COOnPr)2)n. This precursor can be synthesized by anionic ring-opening polymerization of di-n-propylcyclopropane-1,1-dicarboxylate using a polymerization procedure already proved to be living for a similar cyclopropyl monomer. The polyelectrolyte potassium salt was fully characterized by solid-state 13 C NMR, FT-IR, elemental analysis, and thermogravimetry (TGA), providing clear evidence for a very selective and clean hydrolysis. The malonate ion substructure on the polymer is very stable and does not decompose below 350°C. No procedure could be identified to cleanly decarboxylate the polymer to the monosubstituted system. The polymer is very insoluble in water unless high concentrations of potassium hydroxide are used (>1 mol L -1 ), a behavior consistent with the very high symmetry of the polymer and its high tendency to crystallize.
“…The thermal decomposition of lithium oxalate was also previously studied [42][43][44][45]. As is described in the literature, the formation of gas products is highly dependent on the atmosphere in which the TGA measurement is performed [43,44,49]. For example, the gas products and reaction enthalpies in TGA measurements differ depending on the purge gas employed, e.g., in the study of pure lithium oxalate.…”
Section: Flame Retardants and Co 2 Releasementioning
confidence: 99%
“…The precise decomposition of each individual compound/component was not investigated in the present study. However, it was referred to in the literature findings [42,49,50] or postulated on the basis of mass loss and gas detection by IR spectroscopy to determine the decomposition gases (Figure 2). A pre-decomposition in the case of Na fumarate was identified but, due to the much slower process (kinetics), this pre-decomposition process between 400 and 450 • C is not included.…”
Section: Flame Retardants and Co 2 Releasementioning
Lithium-ion batteries are being increasingly used and deployed commercially. Cell-level improvements that address flammability characteristics and thermal runaway are currently being intensively tested and explored. In this study, three additives—namely, lithium oxalate, sodium fumarate and sodium malonate—which exhibit fire-retardant properties are investigated with respect to their incorporation into graphite anodes and their electro/chemical interactions within the anode and the cell material studied. It has been shown that flame-retardant concentrations of up to approximately 20 wt.% within the anode coating do not cause significant capacity degradation but can provide a flame-retardant effect due to their inherent, fire-retardant release of CO2 gas. The flame-retardant-containing layers exhibit good adhesion to the current collector. Their suitability in lithium-ion cells was tested in pouch cells and, when compared to pure graphite anodes, showed almost no deterioration regarding cell capacity when used in moderate (≤20 wt.%) concentrations.
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