Thermal decomposition of propylene oxide

1968 ◽  
Vol 46 (14) ◽  
pp. 2454-2456 ◽  
Author(s):  
T. J. Hardwick
Keyword(s):  
Thermal Decomposition ◽  
Free Radicals ◽  
Propylene Oxide ◽  
First Order ◽  
Temperature Range ◽  
Rate Expression ◽  
Order Rate ◽  
Common Precursor

In the temperature range 402–425 °C, propylene oxide in a toluene medium decomposes to form propionaldehyde (60–70%), acetone (14%), and free radicals (25%). The ratio of products is invarient with temperature, suggesting a common precursor to all three products. Propionaldehyde further decomposes into free radicals. The first order rate expression for propylene oxide disappearance is3.7 × 1012 e−51900/RT s−1.

THE THERMAL DECOMPOSITION OF ETHANE: PART I. INITIATION AND TERMINATION STEPS

1966 ◽  
Vol 44 (4) ◽  
pp. 505-514 ◽  
Author(s):  
M C. Lin ◽  
M. H. Back
Keyword(s):  
Thermal Decomposition ◽  
High Pressure ◽  
Rate Coefficients ◽  
First Order ◽  
Temperature Range ◽  
Order Rate ◽  
Ethyl Radical ◽  
Initiation Reaction ◽  
Ethyl Radicals

The rates of production of methane and butane in the pyrolysis of ethane have been measured over the temperature range 550–620 °C and at pressures of 40–600 mm. At high pressure the rates of formation of both products were first order in ethane, but below 200 mm the first-order rate coefficients decreased. The ratio of methane to butane was consistent with the interpretation that methane is a measure of the initiation reaction and that the combination and disproportionation of ethyl radicals is the main termination step. The order of the decomposition of the ethyl radical with respect to ethane varied between 0.38 and 0.59. The results are discussed in terms of the mechanism of the overall process.

scholarly journals THE THERMAL DECOMPOSITION OF VINYL ETHYL ETHER

1943 ◽  
Vol 21b (5) ◽  
pp. 97-110 ◽  
Author(s):  
Sheng-Nien Wang ◽  
C. A. Winkler
Keyword(s):  
Thermal Decomposition ◽  
Free Radicals ◽  
Ethyl Ether ◽  
Pressure Change ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Temperature Range ◽  
Unsaturated Ether ◽  
Rearrangement Mechanism

Over the temperature range 377° to 448 °C, vinyl ethyl ether has been found to decompose by a first order reaction to give ethylene and acetaldehyde, at a rate given by[Formula: see text]The reaction is capable of sensitizing the decomposition of acetaldehyde and the polymerization of ethylene; this indicates that free radicals are produced during the decomposition of the ether.Nitric oxide exerts virtually no effect upon the rate of ether decomposition, although it does reduce the rates of pressure change of ether-acetaldehyde mixtures to those corresponding to ether decomposition alone.It is suggested that the decomposition of vinyl ethyl ether occurs essentially through a rearrangement mechanism, and that free radicals do not play an important part, owing possibly to the inhibiting character of this unsaturated ether.

Consecutive reactions in the thermal decomposition of phenylalkyldiazirines

1977 ◽  
Vol 55 (20) ◽  
pp. 3596-3601 ◽  
Author(s):  
Michael T. H. Liu ◽  
Barry M. Jennings
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Diazo Compounds ◽  
First Order ◽  
Temperature Range ◽  
Decomposition Reactions ◽  
Consecutive Reactions ◽  
Rate Processes ◽  
Subsequent Decomposition

The thermal decomposition of phenyl-n-butyldiazirine and of phenylmethyldiazirine in DMSO and in HOAc have been investigated over the temperature range 80–130 °C. The intermediate diazo compounds, 1-phenyl-1-diazopentane and 1-phenyldiazoethane respectively have been detected and isolated. The decomposition of phenyl-n-butyldiazirine and the subsequent decomposition of its product, 1-phenyl-1-diazopentane, are an illustration of consecutive reactions. The kinetic parameters for the isomerization and decomposition reactions have been determined. The isomerization of phenylmethyldiazirine to 1-phenyldiazoethane is first order and probably unimolecular but the kinetics for the subsequent reactions of 1-phenyldiazoethane are complicated by several competing rate processes.

THE THERMAL DECOMPOSITION OF PERACETIC ACID IN AROMATIC SOLVENTS

1963 ◽  
Vol 41 (7) ◽  
pp. 1826-1831 ◽  
Author(s):  
F. W. Evans ◽  
A. H. Sehon
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Peracetic Acid ◽  
First Order ◽  
Aromatic Solvents ◽  
Temperature Range ◽  
Polymeric Compounds

The thermal decomposition of peracetic acid in toluene, benzene, and p-xylene was studied over the temperature range 75–95°C. The main products of decomposition were found to be CH4, CO2, CH3COOH; small amounts of methanol, phenols, and polymeric compounds were also detected.The rate of the overall decomposition was first order with respect to peracetic acid, and the results could be explained by postulating the participation of the two simultaneous reactions:[Formula: see text] [Formula: see text]The rate constant of reaction (1) was independent of the solvent, whereas k2 was dependent on the solvent. The ratio k2/k1 was about 10.

Pyrolysis of Trifluoroacetaldehyde

1973 ◽  
Vol 51 (14) ◽  
pp. 2292-2296 ◽  
Author(s):  
Michael T. H. Liu ◽  
Leon F. Loucks ◽  
Robert C. Michaelson
Keyword(s):  
Thermal Decomposition ◽  
High Pressure ◽  
Free Radicals ◽  
Rate Equation ◽  
Pressure Dependence ◽  
Inert Gas ◽  
Order Process ◽  
First Order ◽  
Pressure Region ◽  
High Pressure Region

The thermal decomposition of trifluoroacetaldehyde has been studied over the 460–520 °C temperature range, and at pressures from 4 to 400 mm Hg. The experimental rate equation in the high-pressure region is of the form: Rate = k[CF3CHO]3/2 where[Formula: see text]The results are consistent with a mechanism initiated by a first order process and terminated by a second order recombination of two CF3 free radicals. At lower pressures (40 mm Hg), the ratio of kinit/kterm is pressure dependent and the overall order increases. The effects of added inert gas confirm this pressure dependence.

The thermal decomposition of 2-chloroethanol

1976 ◽  
Vol 29 (3) ◽  
pp. 609 ◽  
Author(s):  
DC Skingle ◽  
VR Stimson
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Chloride ◽  
Ethyl Chloride ◽  
First Order ◽  
Order Rate ◽  
Polar Transition

2-Chloroethanol decomposes at 430-496� into acetaldehyde and hydrogen chloride with first-order rate given by: k1 = 1012.8�1 exp(-229700 � 4000/8.314T) s-l The rate is slightly less than that for ethyl chloride. That acetaldehyde is the product shows that a 1-2 shift of hydrogen has taken place and this is indicative of a polar transition state.The acetaldehyde subsequently decomposes to methane and this decomposition is catalysed by the hydrogen chloride produced.

The Thermal Decomposition of Boron Trimethyl

1962 ◽  
Vol 15 (4) ◽  
pp. 744 ◽  
Author(s):  
AS Buchanan ◽  
F Creutzberg
Keyword(s):  
Thermal Decomposition ◽  
Activation Energies ◽  
Major Product ◽  
Main Reaction ◽  
Static System ◽  
Hydrogen Formation ◽  
First Order ◽  
Rate Expression

The thermal decomposition of boron trimethyl has been studied in a static system in the range 468-513 �C and was found to be first order with a rate expression������������� k1=1.2 x 1012e-[56 000/RT] sec-1. The activation energies for methane and hydrogen formation were found to be 76 and 75 kcal, respectively. The stoicheiometry for the main reaction was found to be ���������������� 2B(CH3)3 → 2CH4 + H2 + [B(CH2)2]2. Preliminary experiments on the photolysis of boron trimethyl indicated that methane was the major product.

KINETICS AND MECHANISMS OF THE PYROLYSIS OF DIMETHYL ETHER: II. THE REACTION INHIBITED BY NITRIC OXIDE AND PROPYLENE

1963 ◽  
Vol 41 (8) ◽  
pp. 1993-2008 ◽  
Author(s):  
D. J. McKenney ◽  
B. W. Wojciechowski ◽  
K. J. Laidler
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Dimethyl Ether ◽  
Chain Process ◽  
Maximal Inhibition ◽  
First Order ◽  
Temperature Range ◽  
Maximum Inhibition ◽  
A Chain

The thermal decomposition of dimethyl ether, inhibited by nitric oxide and by propylene, was studied in the temperature range of 500 to 600 °C. About 1.5 mm of nitric oxide gave maximal inhibition, the rate then being approximately 8% of the uninhibited rate. With propylene, approximately 70 mm gave maximal inhibition, the rate being slightly higher than that using nitric oxide (~12.5% of the uninhibited rate). In both cases the degree of inhibition was independent of the ether pressure. In the maximally inhibited regions both reactions are three-halves order with respect to ether pressure. As the pressure of nitric oxide was increased beyond 10–15 mm, the overall rate increased, and in this region the reaction is first order with respect to both nitric oxide and ether. A 50:50 mixture of CH3OCH3 and CD3OCD3, with enough NO to ensure maximum inhibition, was pyrolyzed. Even at very low percentage decomposition the CD3H/CD4 ratio was approximately the same as that in the uninhibited decomposition, proving that the inhibited reaction is largely a chain process. Detailed inhibition mechanisms are proposed in which the inhibitor is involved both in initiation and termination reactions.

Thermal decomposition of methyl azide

1970 ◽  
Vol 48 (7) ◽  
pp. 1140-1147 ◽  
Author(s):  
M. S. O'Dell Jr. ◽  
B. deB. Darwent
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Order Rate Constant ◽  
First Order ◽  
Hexamethylene Tetramine ◽  
Order Rate

The thermal decomposition of gaseous methyl azide has been investigated at conversions of less than 1% at 155, 170, and 200 °C. The reaction has been shown to be homogeneous and unimolecular, the first-order rate constant being kun1 = 2.85 × 1014 exp − (40 500/RT). The decomposition results in the formation of CH3N(X3∑−) and N2(X1∑g+). The CH3N(X3∑−) do not react with CH3N3 to produce N2, but do form a polymer of composition similar to hexamethylene tetramine and also react with olefins. The major products are N2 and polymer; small amounts of H2 and CH4, but no C2H6, are formed.

Sign in / Sign up

Export Citation Format

Share Document