ANIONIC POLYMERIZATION OF STYRENE

A study of the kinetics of the initiation and propagation reactions in the polymerization of styrene by butyllithium in benzene solution has been made. The initiation has been shown to be first order in styrene and 0.155 order in butyllithium, the propagation to be first order in styrene and half order with respect to active chain ends. The apparent activation energies of the two reactions have been shown to be 18,000 calories and 14,300 calories respectively. The ultraviolet absorption spectra of colored species produced has been measured and compared with others found in similar systems.

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The kinetics of hydration of tricalcium silicate

Canadian Journal of Chemistry ◽

10.1139/v70-554 ◽

1970 ◽

Vol 48 (21) ◽

pp. 3291-3299 ◽

Cited By ~ 4

Author(s):

K. G. McCurdy ◽

B. P. Erno

Keyword(s):

Reaction Mechanism ◽

Intermediate Product ◽

Activation Energies ◽

Tricalcium Silicate ◽

Rate Data ◽

Large Excess ◽

First Order ◽

Kinetics Of ◽

Subsequent Decomposition

An investigation has been made of the kinetics of hydration of tricalcium silicate at several temperatures in a large excess of water in the presence of various added ions. The rate data have been interpreted by a reaction mechanism which involves: (a) the first order hydration of tricalcium silicate to form an intermediate product, 1.5CaO•SiO2, which can react by two pathways, (b) the direct first order decomposition of intermediate, 1.5CaO•SiO2, to form lime and silica or (b′) complexing of intermediate with silica and subsequent decomposition to form lime and silica. This reaction mechanism predicts the rate of production of base during the hydration. The effect of various added ions is interpreted in terms of the proposed mechanism.Rate constants and activation energies for the various steps in the proposed mechanism are reported.

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Thermal Inactivation Kinetics of Human Norovirus Surrogates and Hepatitis A Virus in Turkey Deli Meat

Applied and Environmental Microbiology ◽

10.1128/aem.00874-15 ◽

2015 ◽

Vol 81 (14) ◽

pp. 4850-4859 ◽

Cited By ~ 10

Author(s):

Hayriye Bozkurt ◽

Doris H. D'Souza ◽

P. Michael Davidson

Keyword(s):

Hepatitis A ◽

Thermal Inactivation ◽

Hepatitis A Virus ◽

Weibull Model ◽

Activation Energies ◽

Inactivation Kinetics ◽

Order Model ◽

Decimal Reduction Time ◽

First Order ◽

Kinetics Of

ABSTRACTHuman noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare first-order and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. TheD(decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1 ± 0.0 to 9.9 ± 3.9 min for FCV-F9, 0.2 ± 0.0 to 21.0 ± 0.8 min for MNV-1, and 1.0 ± 0.1 to 42.0 ± 5.6 min for HAV. Using the Weibull model, thetD = 1(time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1 ± 0.0 to 11.9 ± 5.1 min, from 0.3 ± 0.1 to 17.8 ± 1.8 min, and from 0.6 ± 0.3 to 25.9 ± 3.7 min, respectively. Thez(thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3 ± 2.1°C, 11.0 ± 1.6°C, and 13.4 ± 2.6°C, respectively, using the Weibull model. Thezvalues using the first-order model were 11.9 ± 1.0°C, 10.9 ± 1.3°C, and 12.8 ± 1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214 ± 28, 242 ± 36, and 154 ± 19 kJ/mole, respectively, while the calculated activation energies for the first-order model were 181 ± 16, 196 ± 5, and 167 ± 9 kJ/mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks.

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Ultraviolet absorption spectra of the CH2Cl and CHCl2 radicals and the kinetics of their self-recombination reactions from 273 to 686 K

Journal of the Chemical Society Faraday Transactions ◽

10.1039/ft9918702367 ◽

1991 ◽

Vol 87 (15) ◽

pp. 2367 ◽

Cited By ~ 33

Author(s):

Pascal B. Roussel ◽

Phillip D. Lightfoot ◽

Francoise Caralp ◽

Val�ry Catoire ◽

Robert Lesclaux ◽

...

Keyword(s):

Absorption Spectra ◽

Ultraviolet Absorption ◽

Recombination Reactions ◽

Kinetics Of

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THE THERMAL DECOMPOSITION OF HYDROGEN PEROXIDE VAPOUR

Canadian Journal of Research ◽

10.1139/cjr45b-021 ◽

1945 ◽

Vol 23b (5) ◽

pp. 167-182 ◽

Cited By ~ 7

Author(s):

Bruce E. Baker ◽

C. Ouellet

Keyword(s):

Hydrogen Peroxide ◽

Temperature Coefficient ◽

Pure Hydrogen ◽

First Order ◽

Soda Glass ◽

Manometric Method ◽

Apparent Activation Energies ◽

Reaction Vessels ◽

First Time ◽

Kinetics Of

The kinetics of the decomposition of hydrogen peroxide in the vapour state have been studied by a manometric method, with pure hydrogen peroxide at a concentration of about 99.5%. The temperature coefficient of the reaction has been measured for the first time. The pressures ranged from 1 to 2 cm. of mercury and the temperatures from 70° to 200 °C. Pyrex reaction vessels of various sizes and shapes, and also a fused Pyrex and a soda-glass vessel, were used. The reaction was purely heterogeneous, of the first order up to 140 °C. but more complicated at higher temperatures. Identical vessels yielded consistent results. The rates were not affected by air, carbon dioxide, or water vapour, but they varied greatly with the size and shape of the vessel. The reaction was very slow on fused Pyrex and very rapid on soda-glass. In one vessel, the temperature coefficient became negligible above 120 °C. No explosion was detected up to 335 °C. at a pressure of 18 cm. of mercury. The apparent activation energies in various vessels ranged from 13.5 to 18.5 kcal. per mole. A tentative reaction mechanism is suggested.

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THE REACTION OF 2,2-DIPHENYL-1-PICRYLHYDRAZYL WITH SECONDARY AMINES

Canadian Journal of Chemistry ◽

10.1139/v58-249 ◽

1958 ◽

Vol 36 (12) ◽

pp. 1729-1734 ◽

Cited By ~ 25

Author(s):

J. E. Hazell ◽

K. E. Russell

Keyword(s):

Secondary Amine ◽

Rate Constants ◽

Reaction Mechanisms ◽

Hydrogen Abstraction ◽

Activation Energies ◽

Major Product ◽

The Other ◽

Secondary Amines ◽

First Order ◽

Kinetics Of

The reaction of DPPH (2,2-diphenyl-1-picrylhydrazyl) with N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, diphenylamine, and methylaniline has been studied and has been shown to be primarily a hydrogen abstraction process. Two moles DPPH react with 1–1.15 moles secondary amine to give 1.7–1.8 moles 2,2-diphenyl-1-picrylhydrazine and further products.The reaction between DPPH and N-phenyl-1-naphthylamine is first order with respect to each reactant. The reaction of DPPH with the other amines is retarded by the major product 2,2-diphenyl-1-picrylhydrazine and the kinetics of the over-all reaction are complex. However second-order rate constants and activation energies have been obtained using initial rates of reaction. Possible reaction mechanisms are discussed.

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Research on the Kinetics of Nylon Polymerized by Caprolactam Anionic Polymerization Using Adiabatic Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.887-888.955 ◽

2014 ◽

Vol 887-888 ◽

pp. 955-959 ◽

Cited By ~ 1

Author(s):

Hong Kai Zhao ◽

Hong Li Wang

Keyword(s):

Anionic Polymerization ◽

Reaction Kinetic ◽

Reaction Order ◽

Reaction Heat ◽

Exponential Factor ◽

Reaction Systems ◽

First Order ◽

Research Findings ◽

Simulation Results ◽

Kinetics Of

Kinetic parameters were calculated based on the catalytic reaction systems of sodium caprolactam salt、N-75 biuret and at the temperature of 145 to 160 °C. The reaction order was approximately first order. The activation energy was between 73.2−77.1 kJ∙mol−1 and the pre-exponential factor was between 2.9×1011−3.6×1011 mol1−n∙s−1. The calculated reaction heat of 134.5−137.3 J∙g−1 was in consonance with the literature value of 138.6 J∙g−1. The adiabatic reaction kinetic model of caprolactam anion was constructed based on the existing research findings. The coincidence between the simulation results and the experimental data revealed that the model was reasonable and correct.

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Interfacial reactions in multilayers intended for microelectronics devices

MRS Proceedings ◽

10.1557/proc-514-547 ◽

1998 ◽

Vol 514 ◽

Cited By ~ 2

Author(s):

X. Federspiel ◽

F. Voiron ◽

M. Ignat ◽

T. Marieb ◽

H. Fujimoto

Keyword(s):

Phase Formation ◽

Reaction Rate ◽

Experimental Approach ◽

Intermetallic Phase ◽

Activation Energies ◽

Interfacial Reactions ◽

Scanning Calorimetry ◽

Back Scattering ◽

Apparent Activation Energies ◽

Kinetics Of

ABSTRACTThe knowledge of the reaction kinetics which can occur at an interface of a couple of materials, remains a crucial issue to establish the structural limits of a diffusion barrier intended for microelectronic structures.In the past years, the interfacial reactions activated at an interface of a couple of materials, as for example aluminum and titanium, have been analyzed extensively using different experimental tools, as for example: Ruthreford Back Scattering (thickness determination) and Differential Scanning Calorimetry (DSC). Then, these experimental methods were useful to deduce parameters, characterizing the interfacial reactions in bulk samples: apparent activation energies, enthalpy of formation. Because in thin films, the kinetics of the reactions that can be activated at an interface will be different; we studied interfacial reactions in submicronic Al/Ti layers.Taking advantage of the accuracy of the DSC (reaction rate determinations and detection of earlier stages of intermetallic phase formation), our experimental approach consisted in a series of isothermal and non-isothermal DSC experiments on submicron Al/Ti layered structures. From the reaction rate determination, analytical methods as the Kissinger Ozawa approach were used, to determine the apparent activation energies of the phase formation. Also the results allowed to model and discuss the first steps of the interfacial reaction.

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Reactions of pyrazine radical anions in solution. I. Study of the kinetics of the dimerization of pyrazine radical anions

Australian Journal of Chemistry ◽

10.1071/ch9712287 ◽

1971 ◽

Vol 24 (11) ◽

pp. 2287 ◽

Cited By ~ 9

Author(s):

RS Hay ◽

PJ Pomery

Keyword(s):

Absorption Spectra ◽

Electronic Absorption ◽

Rate Constants ◽

Electronic Absorption Spectra ◽

Radical Anions ◽

Light Reaction ◽

First Order ◽

Kinetics Of Reaction ◽

Kinetics Of ◽

Metallic Potassium

The radical anions of pyrazine (pz-.) have been prepared at 294'K by reducing pyrazine (pz) with metallic potassium in 1,2-dimethoxyethane (dme). The resulting reactions of the radical anions are postulat'ed as being described by the equations: The e.s.r, and electronic absorption spectra of all pertinent species were recorded and examined. The kinetics of reaction (1) have been investigated in the dark as well as in light and values of the rate constants have been determined. I n light, reaction (1) did not conform strictly to second-order kinetics and this may be explained by an interaction of pyrazine with dme. The dimer dianion species (-pz-pz-, 2K7) was found to be stable in the dark but decayed slowly in light. This decay was found to exhibit first-order kmetics.

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