The study of polymerization kinetics of methacrylamide by oxidation: Reduction system using potassium permanganate/glycine in aqueous medium

2003 ◽  
Vol 89 (14) ◽  
pp. 3918-3924 ◽  
Author(s):  
A. A. Mirzaei ◽  
H. R. Shaterian ◽  
S. M. Habibi
Keyword(s):  
Aqueous Medium ◽  
Potassium Permanganate ◽  
Polymerization Kinetics ◽  
Reduction System ◽  
Oxidation Reduction ◽  
Kinetics Of

The mechanism of the anionic coordination polymerization of isoprene

1980 ◽  
Vol 45 (9) ◽  
pp. 2391-2399 ◽  
Author(s):  
Miroslav Kašpar ◽  
Jiří Trekoval
Keyword(s):  
Chromatographic Method ◽  
Initial Period ◽  
Reaction Scheme ◽  
Polymerization Kinetics ◽  
Coordination Polymerization ◽  
Initial Concentration ◽  
The Cross ◽  
Gas Chromatographic Method ◽  
Kinetics Of

The polymerization kinetics of isoprene (2-methyl-1,3-butadiene) in benzene with butyllithium as the initiator was investigated by the gas chromatographic method. After completion of the initial period of the reaction, its order with respect to the initial concentration of initiator is negative at the concentrations of the latter between 0.01 and 0.25 mol/l, and positive at higher concentrations. A reaction scheme has been suggested with respect to the "cross" association of butyllithium and of the "living" oligoisoprene.

The effect of electrondonors on the polymerization kinetics of isoprene

1980 ◽  
Vol 45 (12) ◽  
pp. 3338-3346
Author(s):  
Miroslav Kašpar ◽  
Jiří Trekoval
Keyword(s):  
Induction Period ◽  
Ethyl Ether ◽  
Reaction Order ◽  
Propagation Rate ◽  
Reaction Scheme ◽  
Polymerization Kinetics ◽  
Polymerization Rate ◽  
Constant Concentration ◽  
Initial Concentration ◽  
Kinetics Of

The effect of small additions of 1-octene, butyl ethyl ether and triethylamine on the polymerization kinetics of isoprene (2-methyl-1,3-butadiene) in benzene initiated with butyllithium was investigated by employing the GLC analysis. The addition of 1-octane was reflected only in a shorter induction period of the reaction; the effect on the propagation rate was insignificant. With the increasing amount of butyl ethyl ether, the polymerization rate increases linearly, while the reaction order with respect to the concentration of triethylamine is variable and increases from 0.33 to 0.66 with the increasing concentration of the initiator. For a constant concentration of triethylamine, the reaction order with respect to the initial concentration of the initiator was found to vary considerably, reaching even negative values. A reaction scheme was suggested, taking into account the competition between two different solvates of alkyllithium.

scholarly journals Synthesis and Polymerization Kinetics of Rigid Tricyanate Ester

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Single Step ◽  
Polymerization Kinetics ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Diffusion Controlled ◽  
Polymerization Product ◽  
The One ◽  
Kinetics Of

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.

scholarly journals p-HYDROQUINONE AND p-BENZOQUINONE AS HISTOCHEMICAL REAGENTS I. A NEW TETRAZOLIUM METHOD FOR AMINO GROUPS, AND THE MECHANISM OF FORMAZAN STAINING OF PARAFFIN AND FRESH FROZEN SECTIONS

1967 ◽  
Vol 15 (7) ◽  
pp. 404-408 ◽  
Author(s):  
G. G. CARMICHAEL ◽  
STEPHANIE T. K. MANDER
Keyword(s):  
Electron Acceptor ◽  
Thermal Shrinkage ◽  
Frozen Sections ◽  
Amino Groups ◽  
Paraffin Sections ◽  
Tetrazolium Bromide ◽  
Acid Ph ◽  
Reduction System ◽  
Oxidation Reduction ◽  
Fresh Frozen

The staining of amino groups by formazan when dehydrated paraffin sections are incubated in a mixture of hydroquinone and 3-(4,5-dimethyl thiazolyl-2)-2 ,5-diphenyl-2H-tetrazolium bromide at an acid pH is reported. The mechanism of this reaction and of the cytoplasmic deposition of formazan in fresh frozen sections incubated under similar conditions is investigated. It is shown that the oxidation of hydroquinone to semiquinone is responsible for the reaction, the tetrazole acting as electron acceptor. The tissue amino groups, exposed by dehydration and thermal shrinkage, and the nitrogen groupings of phosphobipid behave as "catalysts." The relevant properties of the hydroquinone-benzoquinone oxidation-reduction system are described, and the reactions between benzoquinone and tissue constituents are reviewed.

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