Effects of Operational Parameters on Particle Size Distributions in Methyl Methacrylate Suspension Polymerization

Gonçalves, Odinei Hess; Nogueira, André Lourenço; Araújo, Pedro Henrique Hermes de; Machado, Ricardo Antônio Francisco

doi:10.1021/ie200230j

Cited by 16 publications

(15 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the viscosity of particles is increased, the breakage rate would decrease as the viscous forces inside the particles become greater than the turbulent forces generated by the impeller. In the sticky stage, when the colloidal protection of the dispersant to drops is not enough, the coalescence of drops would increase . When the concentration of added PVA dispersant is lower, the drops with a great initial size would be formed due to the greater interfacial tension between the monomer and water phases, and the coalescence degree of drops in the growth stage would be larger since the drops with less PVA dispersant coverage are more susceptible to coalescence after collision.…”

Section: Resultsmentioning

confidence: 99%

“…used a microscopic method to evaluate the drop/particles sizes and distribution in suspension polymerization of MMA, and a population balance model was used to describe the breakage and coalescence mechanism. Goncalves et al . used the off‐line sampling and sieving method to measure the particle size and studied the effects of reaction conditions (e.g., stirring rate, stabilizer concentration, and stabilizer addition time) on particle size in MMA suspension polymerization.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Online monitoring of drop/particle size and size distribution in liquid–liquid dispersions and suspension polymerizations by optical reflectance measurements

Xie

Pan

Bao

2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

Evolutions of drop/particle size and size distribution in liquid-liquid dispersions and suspension polymerizations of methyl methacrylate (MMA) were monitored by using an online optical reflectance measurement (ORM), and effects of operating parameters such as the agitation rate, concentration of poly(vinyl alcohol) (PVA) dispersant, and initial concentration of poly(methyl methacrylate) (PMMA) in MMA monomer on the Sauter mean diameter (d 32 ) and size distribution of drop/particle were investigated. According to the variations of d 32 of drops/particles with time, four characteristic particle formation stages can be identified for suspension polymerization process. The factors that lead to increase the rate of drop break up, such as increasing of concentration of PVA and decreasing of viscosity of dispersed phase, would postpone the particle growth stage. The d 32 and size distribution breadth of drops/particles were significant increased when the liquid-liquid dispersions or suspension polymerizations were conducted at low PVA concentrations or MMA/PMMA solutions with high PMMA contents were used as the dispersed phase, in consistent with the scanning electron micrograph observation on final PMMA particles. It is clear that ORM can be effectively applied in online monitoring of size and size distribution of drops/particles in the liquid-liquid dispersions and suspension polymerizations.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Online monitoring of drop/particle size and size distribution in liquid–liquid dispersions and suspension polymerizations by optical reflectance measurements

Xie

Pan

Bao

2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…and eq. , respectively

d_{32} = \frac{\sum_{i = 1}^{n} Δ φ_{i}}{\sum_{i = 1}^{n} \frac{Δ φ_{i}}{{\overset{D}{true}}_{i}}} = \frac{1}{\sum_{i = 1}^{n} \frac{Δ φ_{i}}{{\overset{D}{true}}_{i}}}

σ = \frac{\sqrt{\sum_{i = 1}^{n} true[{({\bar{D}}_{i} - d_{32})}^{2} \cdot Δ φ_{i} true]}}{d_{32}}

where

Δ φ_{i}

is the mass fraction retained in the sieve i , and

{\overset{D}{true}}_{i}

is the average diameter considering sieves i and ( i + 1).…”

Section: Methodsmentioning

confidence: 99%

“…Moreover, polymer beads with distinct average size should be able to obtain from batch to batch using the same reactor and with minimal process adaptation. Several experimental studies have been published on the effects of the above operational parameters on the PSD of polymer beads in suspension polymerization . Moreover, predictions of the PSD and the dynamic evolution of the particle formation process by simulation methods have also been reported .…”

Section: Introductionmentioning

confidence: 99%

Effects of polymerization conditions on particle size distribution in styrene‐graphite suspension polymerization process

Cunwei

Chen

et al. 2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

Suspension polymerization in the presence of graphite has been studied in order to determine the effects of some operational parameters on the particle size distribution (PSD). The results showed that, with increasing graphite content, the particle size of the polystyrene/graphite (PS/G) beads increased. Moreover, instability of the suspension polymerization system was found at high amounts of graphite. With increasing initiator concentration, the particle size of the polymer beads increased and the PSD became slightly narrower. Changing the concentration of the suspending agent proved to be an efficient way of controlling the particle size, although its increase led to a broadening of the PSD. Adding the suspending agent in two portions at different times decreased the particle size, maintained a lower concentration of suspending agent, and kept the suspension polymerization system stable. Adjusting the stirring speed proved to be a very efficient means of manipulating the PSD of the PS/G composite beads. The Sauter mean diameter decreased and the PSD was broadened with increasing stirring speed; 400 rpm was identified as an appropriate value to obtain polystyrene/graphite beads with desirable particle size and distribution.

show abstract

“…The low system's viscosity reduced coalescence of the droplets. So the particle size of PS nanocomposites decreased [22,34]. Figure 5 showed that the dimensionless standard deviation values of PS nanocomposites became wider than pure PS slightly.…”

Section: Effect Of Tpp On Particle Size Distribution Of Ps/tpp Beadsmentioning

confidence: 95%

Effects of triphenyl phosphate on styrene suspension polymerization process and flame retardance properties of polystyrene/triphenyl phosphate nanocomposite

Cunwei

Yang

et al. 2016

Colloid Polym Sci

View full text Add to dashboard Cite

Preparation of polystyrene nanocomposites containing flame retardants is difficult to achieve in one step by suspension polymerization. Styrene suspension polymerization was studied to determine the effects of the flame retardant on the polymerization process and properties of polystyrene beads. Triphenyl phosphate (TPP) was used in this work, which can dissolve completely in styrene monomers. The results showed that TPP were nanosized spherical particles, distributed homogenously and uniformly in a polystyrene (PS) matrix, and the formation mechanism of TPP nanoparticles was also investigated. In addition, the effects of TPP on the styrene polymerization process were investigated. With TPP amount increasing, the polymerization time increased significantly; molecular weight of PS nanocomposites also decreased and molecular weight distribution became wide; the particle size distribution (PSD) of the PS nanocomposites became wider than pure PS slightly as the particle size decreased. PS/TPP nanocomposites obtained good flame retardance because of nanodispersed TPP particles in its matrix. In a word, the suspension polymerization method provides a facile approach to prepare PS/TPP nanocomposites with better properties.

show abstract

Effects of Operational Parameters on Particle Size Distributions in Methyl Methacrylate Suspension Polymerization

Cited by 16 publications

References 30 publications

Online monitoring of drop/particle size and size distribution in liquid–liquid dispersions and suspension polymerizations by optical reflectance measurements

Online monitoring of drop/particle size and size distribution in liquid–liquid dispersions and suspension polymerizations by optical reflectance measurements

Effects of polymerization conditions on particle size distribution in styrene‐graphite suspension polymerization process

Effects of triphenyl phosphate on styrene suspension polymerization process and flame retardance properties of polystyrene/triphenyl phosphate nanocomposite

Contact Info

Product

Resources

About