Molecular Weight Distributions in Free-Radical Polymerizations. 2. Low-Conversion Bulk Polymerization

1997 ◽  
Vol 30 (7) ◽  
pp. 1935-1946 ◽  
Author(s):  
Paul A. Clay ◽  
Robert G. Gilbert ◽  
Gregory T. Russell
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Bulk Polymerization ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Radical Polymerizations

Controlling Molecular Weight Distributions Through the Mixing of Low Dispersity Polymer Samples: A Predictive Framework

2019 ◽  
Author(s):  
Maarten Rubens ◽  
Tanja Junkers
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Radical Polymerizations ◽  
Systematic Framework

<div>The physical properties of polymer samples are dependent on the overall shape and breadth of the molecular weight distribution (MWD). A small number of methods are available to tune the shape and characteristics of MWDs based on influencing controlled radical polymerizations and on mixing of individual distributions. However, no systematic framework exists to date to predict the characteristics and shapes of artificial MWDs prior the experiments. In this work we present such framework based on interpolation of individual distributions.</div>

Bulk Polymerization of Styrene using Multifunctional Initiators in a Batch Reactor: A Comprehensive Mathematical Model

2016 ◽  
Vol 14 (1) ◽  
pp. 315-329 ◽  
Author(s):  
E. Berkenwald ◽  
M. L. Laganá ◽  
P. Acuña ◽  
G. Morales ◽  
D. Estenoz
Keyword(s):  
Mathematical Model ◽  
Molecular Weight ◽  
Batch Reactor ◽  
Kinetic Mechanism ◽  
Bulk Polymerization ◽  
Diethyl Ketone ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Global Reaction ◽  
The Mathematical Model

AbstractA detailed, comprehensive mathematical model for bulk polymerization of styrene using multifunctional initiators – both linear and cyclic – in a batch reactor was developed. The model is based on a kinetic mechanism that considers thermal initiation and chemical initiation by sequential decomposition of labile groups, propagation, transfer to monomer, termination by combination and re-initiation reactions due to undecomposed labile groups. The model predicts the evolution of global reaction variables (e.g, concentration of reagents, products, radical species and labile groups) as well as the evolution of the detailed complete polymer molecular weight distributions, with polymer species characterized by chain length and number of undecomposed labile groups. The mathematical model was adjusted and validated using experimental data for various peroxide-type multifunctional initiators: diethyl ketone triperoxide (DEKTP, cyclic trifunctional), pinacolone diperoxide (PDP, cyclic bifunctional) and 1,1-bis(tert-butylperoxy)cyclohexane (L331, linear bifunctional). The model very adequately predicts polymerization rates and complete molecular weight distributions. The model is used to theoretically evaluate the influence of initiator structure and functionality as well as reaction conditions.

Dispersity control in atom transfer radical polymerizations through addition of phenylhydrazine

2018 ◽  
Vol 9 (33) ◽  
pp. 4332-4342 ◽  
Author(s):  
Vivek Yadav ◽  
Nairah Hashmi ◽  
Wenyue Ding ◽  
Tzu-Han Li ◽  
Mahesh K. Mahanthappa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Atom Transfer ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Radical Polymerizations ◽  
Systematic Control

Phenylhydrazine is an effective modifier for conventional ATRP syntheses, providing systematic control over the dispersity of polymers with unimodal molecular weight distributions.

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