A synthetic route to ultra-high molecular weight polystyrene (>106) with narrow molecular weight distribution by emulsifier-free, emulsion organotellurium-mediated living radical polymerization (emulsion TERP)

2016 ◽  
Vol 7 (14) ◽  
pp. 2573-2580 ◽  
Author(s):  
Yukiya Kitayama ◽  
Masayoshi Okubo
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Radical Polymerization ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Living Radical Polymerization ◽  
Synthetic Route ◽  
Narrow Molecular Weight Distribution ◽  
Controlled Living Radical Polymerization ◽  
Ultra High Molecular Weight

We propose a route to synthesizing ultra-high molecular weight (>106) polystyrene (PS) having a narrow molecular weight distribution by controlled/living radical polymerization.

scholarly journals Effects of Illuminance and Heat Rays on Photo-Controlled/Living Radical Polymerization Mediated by 4-Methoxy-2,2,6,6-Tetramethylpiperidine-1-Oxyl

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Eri Yoshida
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Light Source ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Bulk Polymerization ◽  
Living Radical Polymerization ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Controlled Living Radical Polymerization

The effects of illuminance and heat rays released from the light source on the photo-controlled/living radical polymerization of methyl methacrylate were investigated with the aim of strict control of molecular weight. The bulk polymerization was performed at room temperature using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator and (2RS,RS)-azobis(4-methoxy-2,4-dimethylvaleronitrile) as the initiator in the presence of (4-tert-butylphenyl)diphenylsulfonium triflate as the accelerator by irradiation with a high-pressure mercury lamp. The polymerization by the direct irradiation from the light source yielded polymers containing an uncontrolled high-molecular-weight polymer and having the molecular weight distribution over 3. On the other hand, the polymerization by the indirect irradiation with reflective light using a mirror produced polymers with controlled molecular weights with comparatively narrow molecular weight distribution at ca. 1.4. Too high an illuminance caused an increase in the molecular weight distribution. During the polymerization, the monomer conversion increased as the illuminance increased. It was found that the elimination of heat rays from the illuminating light was indispensable for the molecular weight control by the photo-controlled/living radical polymerization.

Bis(phenolate) N-heterocyclic carbene rare earth metal complexes: synthesis, characterization and applications in the polymerization of n-hexyl isocyanate

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83295-83303 ◽  
Author(s):  
Min Zhang ◽  
Jingjing Zhang ◽  
Xufeng Ni ◽  
Zhiquan Shen
Keyword(s):  
Molecular Weight ◽  
Rare Earth ◽  
Metal Complexes ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Rare Earth Metal ◽  
Weight Distribution ◽  
Earth Metal ◽  
Narrow Molecular Weight Distribution ◽  
Rare Earth Metal Complexes

Polyhexyl isocyanantes catalyzed by N-heterocyclic carbene rare earth metal complexes show high molecular weight with narrow molecular weight distribution.

The Application of Supercomputers in Modeling Chemical Reaction Kinetics: Kinetic Simulation of 'Quasi-Living' Radical Polymerization

1990 ◽  
Vol 43 (7) ◽  
pp. 1215 ◽  
Author(s):  
CHJ Johnson ◽  
G Moad ◽  
DH Solomon ◽  
TH Spurling ◽  
DJ Vearing
Keyword(s):  
Molecular Weight ◽  
Differential Equations ◽  
Radical Polymerization ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Euler Method ◽  
Living Radical Polymerization ◽  
Kinetic Simulation ◽  
Stiff Systems ◽  
Chemical Reaction Kinetics

A computer program has been written which employs an implicit Euler method to solve directly the complete set of coupled differential equations which result from an analysis of polymerization kinetics. The program was written to make full use of the speed and power of modern supercomputers, and is suited to the solution of very large stiff systems of differential equations. The benefit of treating each propagation step as a discrete reaction is that information on the evolution of the molecular weight distribution is obtained directly without the need to make perhaps unjustified assumptions such as the steady-state approximation. For illustrative purposes, the method has been applied in the kinetic simulation of 'quasi-living' radical polymerization to assess the effect of experimental variables on the molecular weight, molecular weight distribution, and rate of polymerization. The calculations show that 'quasi-living' radical polymerization can produce polymers with polydispersities approaching those obtained with anionic 'living' polymerizations. Some necessary conditions for the formation of polymers with narrow molecular weight distribution are defined.

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