Kinetic Analysis of Controlled/“Living” Radical Polymerizations by Simulations. 1. The Importance of Diffusion-Controlled Reactions

1999 ◽  
Vol 32 (9) ◽  
pp. 2948-2955 ◽  
Author(s):  
Devon A. Shipp ◽  
Krzysztof Matyjaszewski
Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  

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.


2021 ◽  
Vol 54 (2) ◽  
pp. 874-887
Author(s):  
Liping Yu ◽  
Yong Zhang ◽  
Jirong Wang ◽  
Huihui Gan ◽  
Shaoqiao Li ◽  
...  

2021 ◽  
Author(s):  
Di Zhou ◽  
Liang-Wei Zhu ◽  
Bai-Heng Wu ◽  
Zhi-Kang Xu ◽  
Ling-Shu Wan

The precise design of polymers with well-defined end functionality has received great interest for synthesizing polymeric materials with advanced or distinctive properties. In the past decades, considerable attention has been...


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1683 ◽  
Author(s):  
Nicolas Sbirrazzuoli

Two complex cure mechanisms were simulated. Isoconversional kinetic analysis was applied to the resulting data. The study highlighted correlations between the reaction rate, activation energy dependency, rate constants for the chemically controlled part of the reaction and the diffusion-controlled part, activation energy and pre-exponential factors of the individual steps and change in rate-limiting steps. It was shown how some parameters computed using Friedman’s method can help to identify change in the rate-limiting steps of the overall polymerization mechanism as measured by thermoanalytical techniques. It was concluded that the assumption of the validity of a single-step equation when restricted to a given α value holds for complex reactions. The method is not limited to chemical reactions, but can be applied to any complex chemical or physical transformation.


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