The Kinetics of Emulsion Polymerization: Some Controversial Aspects

Herrera‐Ordóñez, Jorge; Olayo, Roberto; Carro, Shirley

doi:10.1081/mc-200029313

Cited by 18 publications

(6 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In these works, detailed population balances were used to depict the polymerization process; however, complex computational methods and many parameters are required in these models. Comprehensive reviews concerning the mechanisms have appeared such as the ones by Asua, Nomura et al, Chern, Thickett and Gilbert, and concerning controversial aspects, the reader is referred to Herrera‐Ordonez et al, just to mention a few. Some books or compendia include Fitch, Lovell and El‐Aasser, Gilbert, Van Herk, and Chern among others.…”

Section: Introductionmentioning

confidence: 99%

On the Modeling of the Semicontinuous Heterophase Polymerization of Alkyl Methacrylates With Different Water Solubilities

Pérez-García¹,

Alvarado²,

Pérez-Carrillo³

et al. 2015

Macro Reaction Engineering

View full text Add to dashboard Cite

A generalized model is presented here for the semicontinuous heterophase polymerization of methyl and hexyl methacrylate, which have very different water solubility. In this polymerization technique, neat monomer is fed at a controlled rate over a monomer-free aqueous solution of surfactant and initiator, to produce nanometer size particles with controlled molar masses, and high polymer/surfactant ratios similar to those used in conventional emulsion polymerization. For the two monomers studied at three different addition rates, model predictions accurately reproduce conversionversus-time curves, the evolution of particle size, and the number density of particles. The model reveals that the controlling nucleation mechanism shifts from micellar to homogeneous nucleation as the monomer solubility in water increases.

show abstract

Section: Introductionmentioning

confidence: 99%

On the Modeling of the Semicontinuous Heterophase Polymerization of Alkyl Methacrylates With Different Water Solubilities

Pérez-García¹,

Alvarado²,

Pérez-Carrillo³

et al. 2015

Macro Reaction Engineering

View full text Add to dashboard Cite

show abstract

“…Even though there is significant work concerning emulsion polymerization, it still been some uncertainties regarding its kinetics, particularly in what concerns to the particle formation mechanism (nucleation) 1…”

Section: Introductionmentioning

confidence: 99%

On the evolution of the rate of polymerization, number and size distribution of particles in styrene emulsion polymerization above CMC

Carro

Herrera‐Ordóñez

Castillo-Tejas

2010

J. Polym. Sci. A Polym. Chem.

Self Cite

View full text Add to dashboard Cite

This work is an extension of a communication reported by two of the authors [Carro and Herrera-Ordoñ ez, Macromol Rapid Commun 2006, 27, 274], where bimodal particle size distributions (PSD), obtained by asymmetric flow-field flow fractionation (AFFF, AF 4 ), were taken as evidence of certain degree of stability of primary particles. Now, emulsion polymerizations of styrene were performed under conditions employed before by other researchers, intending to examine if the behavior observed is general. The number of particles (N) and PSD were studied by means of dynamic light scattering and AF 4 . By the later, bimodal PSDs were detected in all cases, where the population corresponding to primary particles (diameter <20 nm) depends on reaction conditions. Regarding N, AF 4 results show that it is constant during interval II, in contrast to DLS results. Primary particle coagulation was evidenced as minimums in N evolution and the rate of polymerization curves, monitored by calorimetry and gravimetry, which are enhanced when higher particle number is generated and/or the ionic strength is increased. These results suggest that particle coagulation is not as extensive as it would be expected according to the coagulative theory. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: [3152][3153][3154][3155][3156][3157][3158][3159][3160] 2010

show abstract

“…However, the mechanism of radical capture by particles still remains controversial. 2,3 To date, radical capture has been described by different theories. Gardon 4 as well as Fitch and Tsai 5 considered the radical-particle collisions as the mechanism of entry.…”

Section: Introductionmentioning

confidence: 99%

Brownian Dynamics Simulation of the Capture of Primary Radicals in Dispersions of Colloidal Polymer Particles

Hernández

Tauer

2007

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The kinetics of collision between primary persulfate radicals and colloidal polymer particles, a key issue in emulsion polymerization modeling, is determined by the simulation of Brownian dynamics using a Monte Carlo random flight algorithm. The results obtained confirm the ideal behavior predicted by Smoluchowski's kinetic equation only in colloidal dispersions of very low polymer volume fractions (<0.1%), while at higher values, significant deviations from ideality are observed. This deviation from ideality, designated as the Smoluchowski number (Sm), is found to increase almost linearly with the volume fraction of the dispersion. The kinetic model considering the effect of volume fraction is compared with previous experimental data. A satisfactory explanation for the different functional dependences of the radical entry rate on particle diameter is obtained. It is concluded that the polymer volume fraction in the dispersion plays a major role in the mechanism of radical capture by polymer particles.

show abstract

The Kinetics of Emulsion Polymerization: Some Controversial Aspects

Cited by 18 publications

References 79 publications

On the Modeling of the Semicontinuous Heterophase Polymerization of Alkyl Methacrylates With Different Water Solubilities

On the Modeling of the Semicontinuous Heterophase Polymerization of Alkyl Methacrylates With Different Water Solubilities

On the evolution of the rate of polymerization, number and size distribution of particles in styrene emulsion polymerization above CMC

Brownian Dynamics Simulation of the Capture of Primary Radicals in Dispersions of Colloidal Polymer Particles

Contact Info

Product

Resources

About