Physico-chemical aspects of polyethylene processing in an open mixer. Part 24: Experimental kinetics of aldehyde and carboxylic acid formation

2006 ◽  
Vol 91 (10) ◽  
pp. 2499-2512 ◽  
Author(s):  
F. Gugumus
Keyword(s):  
Carboxylic Acid ◽  
Acid Formation ◽  
Physico Chemical ◽  
Experimental Kinetics ◽  
Kinetics Of

The effect of origin and physico-chemical properties on the kinetics of reduction of mixed NiO-Fe2O3 oxides with hydrogen

1986 ◽  
Vol 51 (10) ◽  
pp. 2098-2108 ◽  
Author(s):  
Milan Pospíšil ◽  
Jan Topinka
Keyword(s):  
Mixed Oxides ◽  
Mutual Influence ◽  
Spinel Phase ◽  
Chemical Properties ◽  
Inhibitory Effect ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Preliminary Annealing ◽  
Kinetics Of ◽  
Kinetics Of Reduction

We investigated the effect of origin and some physico-chemical parameters on the kinetics of reduction with hydrogen of two series of mixed NiO-Fe2O3 oxides differing by their composition, the character of their precursors (mixed crystalline nitrates and coprecipitated hydroxides) and their decomposition temperature.This effect manifested itself by different magnitudes of specific surfaces of the mixed oxides and coherent regions of present phases as well as by different oxidizing abilities of the surface and differences in morphology and phase composition of corresponding samples in both series investigated. Nonlinear or nonmonotonous composition dependences of physico-chemical parameters investigated point to a mutual influence of individual components, which is also a function of the system origin and which modifies its reactivity during its reduction with hydrogen. The kinetics of the reduction was studied thermogravimetrically at 320-410 °C. The reduction of oxides of the hydroxide origin is catalytically accelerated by primarily reduced nickel, whereas in corresponding samples of the nitrate series, the total NiO is bound to the spinel phase and the reduction is delayed. Experimental IR spectra, the effect of preliminary annealing and DTA of the mixed oxides point to an inhibitory effect of water, which is constitutionally bound in trace admixtures of the goethite phase, on the kinetics of reduction of samples in the hydroxide series.

Kinetics of Substitution of 4-Methoxyphenylazo Groups of 2,6-Dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic Acid by Reaction with 4-Nitrobenzenediazonium Cation

1994 ◽  
Vol 59 (7) ◽  
pp. 1665-1672 ◽  
Author(s):  
Jaroslava Horáčková ◽  
Vojeslav Štěrba
Keyword(s):  
Carboxylic Acid ◽  
Rate Constant ◽  
Kinetics Of

Kinetics have been studied of gradual replacement of 4-methoxyphenylazo groups in 2,6-dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic acid (IIIa) by 4-nitrophenylazo groups using the reaction with 4-nitrobenzenediazonium cation (IIc) in acetate and phosphate buffers. The rate constant of replacement of the second methoxyphenylazo group is lower by a factor of ca 60. From the experimentally found pKa values of the corresponding azohydrazone compounds with methoxy, chloro, or nitro substituent at 4-position (IIIa - IIIf) it has been concluded that the 5(3)-(4-methoxyphenylazo)-3(5)-(4-nitrophenylhydrazono) derivative is formed in the first step.

scholarly journals 7-Alkoxy-appended coumarin derivatives: synthesis, photo-physical properties, aggregation behaviours and current–voltage (I–V) characteristic studies on thin films

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10212-10223
Author(s):  
Abhijit Rudra Paul ◽  
Bapi Dey ◽  
Sudip Suklabaidya ◽  
Syed Arshad Hussain ◽  
Swapan Majumdar
Keyword(s):  
Thin Films ◽  
Carboxylic Acid ◽  
Physical Properties ◽  
Chemical Characteristics ◽  
Coumarin Derivatives ◽  
Design Synthesis ◽  
Electrical Switching ◽  
Physico Chemical ◽  
Current Voltage

In this article, we demonstrate the design, synthesis and physico-chemical characteristics, including electrical switching behaviours of long alkoxy-appended coumarin carboxylate/carboxylic acid in thin films.

THE TRANSMISSION OF POLAR EFFECTS: IV. THE KINETICS OF ESTERIFICATION WITH DIAZODIPHENYLMETHANE OF SUBSTITUTED HETEROCYCLIC CARBOXYLIC ACIDS

1966 ◽  
Vol 44 (13) ◽  
pp. 1493-1499 ◽  
Author(s):  
Keith Bowden ◽  
D. C. Parkin
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Rate Coefficients ◽  
Relative Ability ◽  
Indole Carboxylic Acid ◽  
Kinetics Of ◽  
Electron Effects

The rate coefficients for the reaction with diazodiphenylmethane, in ethanol at 30.0°, of a number of substituted indole-2-carboxylic acids, indole-3-carboxylic acids, coumarin-3-carboxylic acids, coumarilic acids, and N-phenylglycines have been determined. The effect of substitution is assessed by use of adapted Hammett and Dewar–Grisdale relations. The relations give good correlations for oxygen-ring heterocyclic systems, and the relative ability of the systems to transmit π-electron effects has been determined. An anomalous perturbing effect appears to operate in the indole-carboxylic acid systems.

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