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1.
L.S. Kochneva N.A. Kopylova L.M. Terman Yu.D. Semchikov 《European Polymer Journal》1979,15(6):575-580
Zinc chloride reduces the rate of thermal and thermooxidative decompositions of polymethacrylic esters and increases the thermal decomposition rate of polyacrylic esters. Mechanisms of the thermal decompositions of polymethacrylates and polyacrylates in the presence of ZnCl2 have been suggested.For thermal decomposition polymethacrylic esters, the rate of depolymerization decreases due to the formation of cycles in a polymer chain by reaction of Zinc chloride with neighbouring ester groups. For thermooxidative decomposition of polymethacrylates, ZnCl2 decreases also the rate of initiation of depolymerization and causes decomposition of hydroperoxide groups by a heterolytic mechanism. The increase in thermal decomposition rate of polyacrylic esters results from the high activity of complexes of ester groups and ZnCl2 in decomposition reactions with formation of alcohol and CO2 through Cameron mechanism. 相似文献
2.
On the Mechanism of the Formations of Chromium(IV)oxide from Chromyl Chloride The decomposition of chromyl chloride in the temperature range from 380 to 400°C leads with increasing oxygen pressure to chromium oxides containing up to nearly 90% of CrO2. The interaction with the chlorine prevents a quantitative formation of CrO2. Up to 315°C during the decomposition of chromyl chloride chromium oxides of higher valencies are formed separating chlorine and taking up oxygen simultaneously. By working in flowing oxygen it could be proved that the decomposition goes at lower temperatures via the nondetectable CrO3. By heating gradually and by removing the chlorine as far as possible stoichiometric CrO2 at oxygen pressures above 60 atm could be obtained. 相似文献
3.
Adrian A. Caraculacu 《Journal of polymer science. Part A, Polymer chemistry》1966,4(7):1839-1849
The selectivity of the phenolysis reaction of a chlorine atom bound to a tertiary carbon ClT on a macromolecular model, i.e., the copolymer of vinyl chloride–isopropenyl chloride, was verified. The phenolysis reaction can be used as a chemical method to determine ClT in the copolymers. Phenolic polyelectrolytes are obtained as products. The increase of the ClT content leads to an appreciable decrease of the thermal stability of the polymer. The thermal decomposition by dehydrochlorination is a chain reaction. The γ and ultraviolet radiolysis processes did not reveal a remarkable influence of ClT; the samples with an increased ClT content showed a decreased stability towards sunlight. One concludes that when ClT is present in PVC it can initiate the decomposition reaction at lower temperatures than would be expected. 相似文献
4.
A. M. Lyons E. M. Pearce A. M. Mujsce 《Journal of polymer science. Part A, Polymer chemistry》1990,28(2):245-259
The thermal decomposition of complexes between poly(2-vinylpyridine) (P2VPy) and copper chloride was investigated by several techniques, including thermogravimetric analysis and mass spectrometry. P2VPy was selected as the host polymer for two reasons: its ability to form complexes with copper compounds which are soluble in high concentrations, and because it forms essentially no char upon pyrolysis. The decomposition mechanism of P2VPy changes significantly upon complexation with copper compounds. P2VPy was initially thought to be an ideal ligand for the pyrolytic formation of pure copper owing to its low carbon yield upon thermal decomposition. The presence of copper chloride during polymer decomposition alters the decomposition mechanism of the polymer and accounts for significant yields of carbonaceous char. The magnitude of this effect is dependent upon the quantity of copper present. Polymer char yields as high as 41 wt% have been obtained when each pyridine moiety is complexed by CuCl2. Studies based on the model compound Cu(2-picoline)2Cl2 indicate that the diffusion length of released volatiles plays a significant role in the observed decomposition mechanisms. 相似文献
5.
Ludwig Maier 《Helvetica chimica acta》1966,49(8):2458-2465
The reaction of methyl chloride and methyl bromide with white phosphorus is studied under a variety of conditions, and the conditions giving a high yield of tetramethylphosphonium chloride and bromide are established. Thermal decomposition of [(CH3)4P]+Cl? gives (CH3)3P and CH3Cl, and alkaline decomposition of [(C4H9)3(C12H25)P]+Cl? gives C4H10 and (C4H9)2(C12H25)P?O. 相似文献
6.
V. A. Borisov A. N. D’yachenko R. I. Kraidenko 《Russian Journal of Inorganic Chemistry》2012,57(7):923-926
A reaction between cobalt oxide and ammonium chloride was studied. A possible mechanism of this reaction was determined by TGA and DSC. The reaction products were identified by IR spectroscopy, chemical and XRD analyses. A multistage mechanism was established for reaction between cobalt oxide and ammonium chloride. Cobalt chloride was determined to be the final product; the reaction occurs via the formation and decomposition of (NH4)3CoCl5, (NH4)2CoCl4, and NH4CoCl3. 相似文献
7.
The thermal decomposition of Pt(NH3)4Cl2-H2O can be followed by means of the Derivatograph with simultaneous t.g., d.t.g., d.t.a. and e.g.a. The decomposition in a nitrogen atmosphere involves three stages, with maximum rates at 100, 250 and 315°C. Possible reaction path ways release chlorine or nitrogen. A simultaneous evolved gas analysis showed that chlorine is not developed. By direct and indirect methods, it was proved that the gases released during the decomposition to platinum are water, ammonia, hydrogen chloride and nitrogen. 相似文献
8.
The decomposition of dimethyldioxirane induced by the chloride anion has been investigated by methods of infrared chemiluminescence
and quantum chemistry. The reaction leads to efficient generation of singlet excited molecular oxygen 1O2 (the excitation yield in acetone is 61%). A mechanism of peroxide decomposition is proposed in which the key reactions are
the addition of the chloride ion to an oxygen atom of dioxirane, resulting in dioxirane ring opening and the formation of
the 2-chlorooxy-2-hydroxy propane alcoholate (k
1), and the interaction of the latter with another dimethyldioxirane molecule. This interaction results either in the formation
of an adduct, which further decomposes to evolve 1O2, and catalyst regeneration (k
2) or in the formation of the 2-chloroxyisopropyl radical, which leads to the irreversible consumption of the chloride ion
catalyst (k
3). The decay kinetics of the infrared chemiluminescence of 1O2 has been studied in a wide range of reactant concentrations. The temperature dependence of the rate constant of the reaction
of dimethyldioxirane with the chloride ion has been determined by a kinetic analysis of the mechanism proposed: log(2
k
1) = (11.1 ± 0.7) − (46 ± 4)/Θ, where Θ = 2.3RT kJ/mol. Estimation of the ratio of the rates of the reaction of the 2-chlorooxy-2-hydroxy propane alcoholate with dimethyldioxirane
via two pathways (k
3/k
2) has demonstrated that the fraction of the process involving electron transfer does not exceed 1.5% under the experimental
conditions examined. Nevertheless, the latter reaction, which withdraws the chloride ion from the catalytic cycle of dimethyldioxirane
decomposition yielding singlet oxygen, has a marked effect on the overall kinetics of the process. 相似文献
9.
《Journal of Inorganic and Nuclear Chemistry》1979,41(4):517-523
Two chloride containing cerous carbonate compounds, formulated as Ce3Cl(CO3)4 and Ce4Cl(OH)3(CO3)4, have been synthesized by carbonation of cerous oxychloride in pyridine/H2O mixtures at elevated temperatures. Pyridinium chloride has been identified as a reaction product. These compounds have been characterized by IR spectral and X-ray diffraction techniques. Thermal decomposition studies indicate that the final solid product at 873 K in the absence of steam is a mixture of ceric oxide and cerous oxychloride, the amount of each being dependent upon the Cl−/Ce ratio in the initial compound. The thermal reaction pathway of both compounds involves initial decomposition to cerous dioxymonocarbonate and cerous oxychloride with concomitant carbon dioxide evolution. The cerous dioxymonocarbonate subsequently oxidizes at higher temperature to ceric oxide via carbon monoxide evolution. The utility of these new cerium(III) chlorocarbonate phases in heat cycles for water splitting is discussed. 相似文献
10.
The thermal properties of some organotin complexes of general structure (4-ZC6H4)2SnCl2.L2 (Z=Me, CF3, F, Cl, OMe and H; L2 = 2,2′ -bipyridyl and 4,4′ -dimethyl-2,2′ -bipyridyl) are reported. The thermal data obtained by Differential Thermal Analysis (DTA) for these complexes is reported. Thermal decomposition experiments for some of the complexes are described and indicate a disproportionation of the complexes into the aryltin trichloride complex and the triaryltin chloride. The controlled decomposition provides a possible alternative preparative route to some aryltin trichloride complexes. 相似文献
11.
Dehydrated ammonium carnallite was synthesized with bischofite from salt lake and ammonium chloride solution in a 1:1 molar
ratio of MgCl2:NH4Cl, dehydrated at 160°C for about 4 h. The yield was above 85%. The product was then mixed with solid-state ammonium chloride
with a 1:4 mass ratio for the further dehydration at 410°C. The decomposition of NH4Cl made a pressure of NH3 at 30.5 kPa to prevent the hydrolysis of ammonium carnallite. The anhydration of magnesium chloride was achieved at 700°C.
The results showed that anhydrous magnesium chloride contains magnesium oxide in an amount that was less than 0.1% by weight.
XRD pattern and SEM micrograph showed a good dispersion of ammonium carnallite and anhydrous magnesium chloride crystals with
well-distributed big grains, just enough to meet the need for the production of magnesium metal in the electrolysis process.
__________
Translated from Chinese Journal of Applied Chemistry, 2005, 22(8) (in Chinese) 相似文献
12.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(10):810-813
The crystal structure of hydroxytropylium chloride, C7H6OH+·Cl−, the hydrochloride salt of tropone, is described, which represents the first crystallographic characterization of an unfunctionalized hydroxytropylium ion. Crystals were obtained serendipitously from a sample of chlorotropylium chloride after partial hydrolysis. This highlights the role of hydroxytropylium ions as an intermediate in the hydrolytic decomposition of halotropylium halides to tropone. The solid‐state structure consists of layers, in which the hydroxytropylium and chloride ions interact via both strong hydrogen bonds formed by the hydroxy protons and weaker hydrogen bonds formed by the tropylium protons to produce a two‐dimensional network. 相似文献
13.
Gong-Zheng Zhang Jian Zhang Huan-Jun Li Jun Wang Shan Zhao 《Journal of Thermal Analysis and Calorimetry》2014,117(2):867-873
Commercial polystyrene has been chemically modified with 4,4-dinitro valeryl chloride by use of Friedel–Crafts acylation reaction in the presence of anhydrous aluminum chloride in a mixture of 1,2-dichloroethane and nitrobenzene. The modified polystyrene containing –COCH2CH2C(NO2)2CH3 fragments in side phenyl rings, named gem-dinitro valerylated polystyrene (GDN-PS), was characterized by an Ubbelohde’s viscometer, FTIR, and 1H NMR spectroscopy. Simultaneous thermogravimetry–differential thermal analysis and differential scanning calorimetry (DSC) have been used to study thermal behavior of the polymer. The results of TG analysis revealed that the main thermal degradation for the GDN-PS occurs during two temperature ranges of 200–300 and 300–430 °C. The DTA curve of GDN-PS is showing a visible exothermic peak at 253.8 °C corresponding to the decomposition of gem-dinitro valeryl groups. The decomposition kinetic of the gem-dinitro groups for GDN-PS with degree of substitution (DS) 11 % was studied by non-isothermal DSC under various heating rates. Kinetic parameters such as activation energy and frequency factor for thermal decomposition of GDN-PS with DS 11 % were evaluated via the ASTM E698 and two isoconversional methods. 相似文献
14.
The mechanism of the chloride ion-induced catalytic decomposition of methyl(trifluoromethyl)dioxirane in trifluoroacetone
was studied at the MP4//MP2/6-31+G(d) level of theory. The solvated chloride ion interacts with dioxirane to form an ion-dipole
pair, which is transformed into the key intermediate ClO—C(Me)(CF3)—O− acting as a chain carrier in the catalytic decomposition of dioxirane. The generation of singlet oxygen occurs during the
transformations of this intermediate on the singlet potential energy surface. 相似文献
15.
Experimental evidence is presented for a unimolecular gas-phase Wagner-Meerwein shift in neopentyl chloride pyrolysis. In the decomposition of α,α-neopentyl chloride-d2 at 445°C, maximally inhibited by cyclohexene, the initial products were isotopically pure 2-methyl-1-butene-d2 and 2-methyl-2-butene-d1. Rearrangement, accompanied by loss of either α- or γ-hydrogen in the formation of hydrogen chloride, is consistent with an incipient ion-pair type of transition state. The cyclohexene maximally inhibited pyrolysis of neopentyl chloride was also examined over the temperature range 424–478°C and Arrhenius parameters of E, 258.7 kJ/mole and logA/sec?1, 13.78, were determined. 相似文献
16.
A. V. Levanov E. E. Antipenko V. V. Lunin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(3):519-522
Relying on experimental data on products and the kinetic features of the complex reaction between O3 and Cl−(aq), we establish that the primary stage of the reaction proceeds via a mechanism in which an oxygen atom is transferred
from an ozone molecule to a chloride ion. Analyzing the thermodynamic parameters of the primary stage, we conclude that a
long-lived intermediate complex of a chloride ion and ozone is initially formed. The mechanism of acid catalysis in the reaction
between O3 and Cl−(aq) is described as the formation of a protonated intermediate complex, HO3Cl, in the acidic medium and its rapid decomposition toward the formation of products. 相似文献
17.
Thermal decomposition of rhodium(III) chloride under inert, oxidative and reductive gas atmospheres was investigated in order
to determine its thermal properties. Stoichiometries of the reactions occurring during heating are described. it is suggested
that the chemical formula of soluble rhodium(III) chloride should be presented as RhCl3·HCL·xH2O. Cold crystallisation of anhydrous rhodium(III) chloride at a temperature of about 500°C was established. The procedure
for quantitative determination of volatile matter (water and hydrochloric acid) content and rhodium content by thermogravimetry
is given and discussed. The repeatability and reproducibility of the method are estimated.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
The thermal decompositions of ethyltrichloro-and ethyltrimethyl-silane have been studied in the gas phase at 823K. The main primary process in each case is the dehydrosilylation reaction X3SiCH2CH3 → X3SiH+CH2 = CH2 (X = Cl or Me), though several additional products are formed, mainly in secondary reactions. It is concluded that the dehydrodesilylations involve a radical chain sequence, and that the formation of vinyl chloride by dehydrosilylation during the thermolysis of (2-chloroethyl) trichlorosilane probably also follows a radical pathway rather than the four-centre molecular process previously suggested.The following reactions at ca. 823K have also been briefly examined: (i) the thermal decomposition of trichlorosilane; (ii), the interaction of ethylene and tri-chlorosilane; (iii) the thermal decomposition of vinyltrichlorosilane. 相似文献
19.
Thermal decompositions of zinc(II) chloroacetate and its complexes with nicotinamide and caffeine were studied by means of TG/DTG, DTA, IR and mass spectroscopy. Thermal analysis showed that presence of the halogen significantly influenced the thermal decomposition. Decompositions may be characterized as two step reactions (release of nicotinamide or caffeine followed by pyrolysis of the carboxylate anion). Zinc chloride, CO, CO2, CH2O, ClCH2CHO were found in gaseous products of the thermal decomposition. 相似文献
20.
Basic Aluminum Salts and their Solutions. X. NMR-Investigations on the Tridecameric Al-Oxo-Hydroxo Cation Using solid-state high resolution 27Al-NMR it is shown that in the basic aluminum chloride with a degree of alkalinity r = OH/Al = 2.5 cations of the [Al13O4(OH)25(H2O)11]6+ type exist. The 1H-NMR detects besides the constitutional water still an amount of mobile, enclosed H2O molecules which can be removed by thermal treatment at 104°C. The 27Al spectrum of the aqueous solutions of the chloride shows only one peak at 62.5 ppm which is characteristic for the tridecameric cation. Adding HCl to the solution causes a decomposition to low-molecular species (peak at 0 ppm). Adding NaOH to the aqueous solution of the chloride effects a rearrangement of the tridecameric cations to higher molecular particles which are no more accessible by 27Al-NMR. 相似文献