Reaction kinetics of vinyl acetate emulsion polymerization

Chern, Chorng–Shyan; Poehlein, Gary W.

doi:10.1002/app.1987.070330623

Cited by 12 publications

(7 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Desorption of pure VAc oligomers is favored over vinyl versatate‐containing radicals due to the same considerations of hydrophobicity. When Chern and Poehlein considered the monomer‐unit radical transport out of particles, they noted that there was a relationship among the rate constant for desorption of a monomeric radical, k dm , the diffusion coefficient of the monomeric radical, D m , and the particle size, d, shown as below8: Since the concentration of monomeric radicals in monomer‐swollen particles is extremely low, the system inside particles can be taken as a dilute solution in the nucleation period. Thus, the diffusion of monomer‐unit radical in the particle phase follows the theory of molecular diffusion in dilute solution 9…”

Section: Resultsmentioning

confidence: 99%

A Racemic Polar Cobalt Phosphonate with Weak Ferromagnetism

Huang

Bao

Ling

et al. 2012

Chemistry A European J

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

A Racemic Polar Cobalt Phosphonate with Weak Ferromagnetism

Huang

Bao

Ling

et al. 2012

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…This is presently the generally accepted reaction locus. [4] While the aqueous phase is not an important locus of polymerization with respect to the relative quantities of monomer converted to polymer, the species formed in this phase are of importance because of their influence on the number of particles formed through the reaction (homogeneous -coagulative nucleation). Thus, in surfactant free polymerizations, the number of particles would be proportional to the number of chains initiated in solution (which grow to the critical size and then precipitate) with a possible reduction in this number due to radical combinations or capture by a particle before homogeneous particle formation occurs and to coagulative nucleation.…”

Section: Introductionmentioning

confidence: 99%

Surfactant Concentration Effects on the Aqueous Phase Polymerization of Vinyl Acetate

Martínez‐Gutiérrez

Ovando‐Medina

Peralta

2009

Macromolecular Symposia

View full text Add to dashboard Cite

Summary: Vinyl acetate (VAc) in concentrations below the water saturation value was polymerized by batch processes at 60 8C using low surfactant concentrations of sodium dodecyl sulfate (SDS) and potassium persulfate (KPS) as initiator. The effects of surfactant concentration on the reaction kinetics, particle formation and molecular weight were studied. It was found that the average particle diameters decrease between 277 and 18.7 nm as the surfactant concentration is increased from 0 to 11 mmol/L, whereas the weight average molecular weight (Mw) decreases also, with values between 8.7 Â 10 5 Mw 1 Â 10 5 Da. It was observed that particle size distributions are strongly affected by the addition of small amounts of surfactant. For the low monomer concentrations used in the polymerizations (0.0137 g/cm 3 of water), particles were very stable and no coagulation was observed. High reaction rates were found in all polymerizations. When no SDS was added to the system, lower polymerization rates were obtained at the onset of the reaction due to the low rate of particle formation. The behavior of polymerization rate was inversely proportional to the surfactant concentration, which was ascribed to the increase in the average number of radicals per particle.

show abstract

“…Desorption of pure VAc oligomers is favored over vinyl versatate-containing radicals due to the same considerations of hydrophobicity. When Chern and Poehlein considered the monomer-unit radical transport out of particles, they noted that there was a relationship among the rate constant for desorption of a monomeric radical, k dm , the diffusion coefficient of the monomeric radical, D m , and the particle size, d, shown as below 8 :…”

Section: Figurementioning

confidence: 99%

Miniemulsion and macroemulsion copolymerization of vinyl acetate with vinyl versatate

Wu¹,

Hong²,

Cordeiro³

et al. 2002

J of Applied Polymer Sci

View full text Add to dashboard Cite

ABSTRACT:The miniemulsion and macroemulsion polymerization of vinyl acetate with vinyl versatate in batch and semibatch systems was investigated. Vinyl versatate was added either as an emulsion with the vinyl acetate, or as a neat liquid stream. In the batch runs, there is a poor dispersion of vinyl versatate during the nucleation period for the runs in which the vinyl versatate was added neat at the beginning of the polymerization. This led to smaller particles, lower polymerization rate, and different polymer composition evolution when compared with runs in which the vinyl versatate was emulsified with the vinyl acetate. In seeded semibatch runs, residual surfactant in the seed latex, along with the propensity for homogeneous nucleation in vinyl acetate emulsions, resulted in continuing nucleation during the entire semibatch interval. The polymerization rate was primarily affected by monomer feed rate rather than the feeding mode. The effect of monomer feeding mode on copolymer composition was weak when the semibatch feed rate was low, indicating some level of vinyl versatate mass transfer resistance. In all runs, only one glass transition temperature was observed, indicating effective copolymerization.

show abstract

Reaction kinetics of vinyl acetate emulsion polymerization

Cited by 12 publications

References 38 publications

A Racemic Polar Cobalt Phosphonate with Weak Ferromagnetism

A Racemic Polar Cobalt Phosphonate with Weak Ferromagnetism

Surfactant Concentration Effects on the Aqueous Phase Polymerization of Vinyl Acetate

Miniemulsion and macroemulsion copolymerization of vinyl acetate with vinyl versatate

Contact Info

Product

Resources

About