A rapid quenched-flow device for the study of homogeneous polymerization kinetics

2002 ◽  
Vol 73 (2) ◽  
pp. 411-415 ◽  
Author(s):  
Curtis B. White ◽  
Kimberly A. Rosaaen ◽  
Clark R. Landis
Keyword(s):  
Polymerization Kinetics ◽  
Flow Device ◽  
Homogeneous Polymerization

A novel high-vacuum and variable-temperature stopped-flow device for high-purity polymerization kinetics

1991 ◽  
Vol 47 (1) ◽  
pp. 271-275 ◽  
Author(s):  
M. Villesange ◽  
A. Rives ◽  
C. Bunel ◽  
J-.P. Vairon ◽  
M. Froeyen ◽  
...  
Keyword(s):  
High Purity ◽  
Variable Temperature ◽  
High Vacuum ◽  
Polymerization Kinetics ◽  
Stopped Flow ◽  
Flow Device

Evaluation of the disinfection potential of low chlorine concentrations in tap water using immobilised enterococcus faecium in a continuous flow device

1997 ◽  
Vol 35 (11-12) ◽  
pp. 77-80 ◽  
Author(s):  
A. Wiedenmann ◽  
M. Braun ◽  
K. Botzenhart
Keyword(s):  
Distribution System ◽  
Enterococcus Faecium ◽  
Continuous Flow ◽  
Tap Water ◽  
Test System ◽  
Batch Experiments ◽  
Membrane Filters ◽  
Upper Limit ◽  
Flow Device ◽  
Faecal Streptococci

A simple continuous flow device in which bacteria were immobilised on membrane filters and flushed with tap water with free chlorine residuals of 0.05, 0.1, 0.2 and 0.4mg/L at pH 7.7 and 10°C, has been used for disinfection experiments with faecal streptococci. A 99.99% reduction of Enterococcus faecium was observed between 3.4–5.2min (0.05mg/L), between 2.8–4.1min (0.1mg/L), between 1.7–3.1min (0.2mg/L) and between 0.8–2.1min (0.4mg/L). CT-products covered a range of 0.17 (0.05mg/L, lower limit) up to 0.85mg/L/min (0.4mg/L, upper limit). The test system is suggested as a more reliable alternative to batch experiments when the disinfection potential of low chlorine concentrations acting for several minutes has to be evaluated. The system cannot be used to demonstrate exact reduction kinetics but it allows the calculation of CT values and the evaluation of the disinfection potential of chlorinated water at any point of a distribution system where initial chlorine concentrations may have already remarkably declined.

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.

Diffusion Interface Technique for Determination of Initial Polymerization Kinetics

2005 ◽  
Vol 26 (5) ◽  
pp. 357-360 ◽  
Author(s):  
Miroslav Skoumal ◽  
Igor Cejpek ◽  
Chung Ping Cheng
Keyword(s):  
Polymerization Kinetics ◽  
Diffusion Interface
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