A Comprehensive Kinetic Model for the Free-Radical Polymerization of Vinyl Chloride in the Presence of Monofunctional and Bifunctional Initiators

2004 ◽  
Vol 43 (20) ◽  
pp. 6382-6399 ◽  
Author(s):  
Apostolos Krallis ◽  
Costas Kotoulas ◽  
Stratos Papadopoulos ◽  
Costas Kiparissides ◽  
Jacques Bousquet ◽  
...  
Keyword(s):  
Free Radical ◽  
Kinetic Model ◽  
Radical Polymerization ◽  
Vinyl Chloride ◽  
Free Radical Polymerization ◽  
Bifunctional Initiators

scholarly journals The free radical polymerization of the vapours of certain vinyl derivatives

1946 ◽  
Vol 187 (1008) ◽  
pp. 37-53 ◽  
Keyword(s):  
Free Radical ◽  
Radical Polymerization ◽  
Vinyl Chloride ◽  
Free Radical Polymerization ◽  
Radical Mechanism ◽  
Methyl Radicals ◽  
Kinetic Methods ◽  
Free Radical Mechanism ◽  
Vinyl Derivatives ◽  
Styrene Butadiene

The free radical polymerization of the vapours of vinyl chloride, acrylic nitrile, styrene, butadiene and methyl isopropenyl ketone has been investigated using methyl radicals from photo-decomposing acetone. Although all the reactions do not exhibit ideal behaviour it is possible by the application of kinetic methods to measure the ratio of the propagation to the termination coefficients for these polymerization reactions. In this way relative values of the quantitative tendency for a molecule to polymerize by a free radical mechanism can be computed.

scholarly journals Empirical models for viscosity variation in bulk free radical polymerization

2004 ◽  
Vol 58 (9) ◽  
pp. 393-400 ◽  
Author(s):  
Silvia Curteanu ◽  
Victor Bulacovschi
Keyword(s):  
Experimental Data ◽  
Molecular Weight ◽  
Free Radical ◽  
Kinetic Model ◽  
Radical Polymerization ◽  
Model Simulation ◽  
Free Radical Polymerization ◽  
Empirical Models ◽  
Viscosity Data ◽  
Simulation Results

The validity of the Lyons-Tobolsky equation for bulk polymerization systems was verified by comparing simulation results to experimental data for different reaction conditions (temperature and initiator concentration). In this model, formerly applied for solution polymerization, the viscosity of the reaction mass was used instead of solvent viscosity. For example, the chemically initiated free radical polymerization of methyl methacrylate was considered to be achieved in a batch bulk process. In the Lyons-Tobolsky equation, the viscosity was calculated using the values of the conversion and molecular weight resulting from the kinetic model simulation. Consequently, a general discussion about the concordance between the simulation and experiment was useful, especially to emphasize the causes that generate modeling errors. It is more convenient to estimate the viscosity independently of conversion and molecular weight and, in this way, without solving the kinetic model. Empirical relations which correlate viscosity with time were elaborated using experimental viscosity data. Two kinds of models were proposed: a) two fifth order polynomials corresponding to the conversion domains before and after the gel effect; b) a model that fits the experimental data well in the whole conversion domain. Generally, these empirical models provide good simulation results and they can be easily handled.

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