Miniemulsion Polymerization Stabilized by a Well-Defined, Amphiphilic Gradient Poly(styrene-co-acrylic acid) Copolymer

2006 ◽  
Vol 59 (8) ◽  
pp. 544 ◽  
Author(s):  
Catherine Lefay ◽  
Maud Save ◽  
Bernadette Charleux ◽  
Stéphanie Magnet
Keyword(s):  
Particle Size ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Butyl Acrylate ◽  
Miniemulsion Polymerization ◽  
Radical Copolymerization ◽  
Water Soluble ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Free Radical Copolymerization

The nitroxide-mediated controlled free-radical copolymerization of styrene (St) and acrylic acid (AA) was used to synthesize a well-defined poly(St30%-co-AA70%) amphiphilic gradient copolymer. The latter proved to be an efficient stabilizer in the 45 wt.-% solids content, batch miniemulsion polymerizations of St and of mixtures of methyl methacrylate/n-butyl acrylate (35/65 w/w). With 2,2´-azobisisobutyronitrile as an oil-soluble initiator, polystyrene latexes with a very narrow particle distribution were obtained, whereas the water-soluble initiator, potassium persulfate, led to broad, multimodal particle size distributions. Such results were explained by the contribution of two nucleation mechanisms: droplet nucleation and homogeneous nucleation. In contrast, the poly(methyl methacrylate-co-n-butyl acrylate) latexes exhibited larger particle size and narrower particle size distributions with persulfate initiator, than the polystyrene latexes.

Flocculation Effects of Hydrophobically Modified Polyacrylamides for Tailing Slurry

2012 ◽  
Vol 602-604 ◽  
pp. 781-784 ◽  
Author(s):  
Da Ping Wu ◽  
Li Na Zhu ◽  
Yan Lin Sun
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Methyl Methacrylate ◽  
Butyl Acrylate ◽  
Water Solution ◽  
Insoluble Fraction ◽  
Radical Copolymerization ◽  
Free Radical Copolymerization ◽  
Hydrophobically Modified ◽  
Monomer Content

The hydrophobically modified polyacrylamides (PAM) were synthesized using butyl acrylate (BA) and methyl methacrylate (MMA) as hydrophobic monomers, via water solution free radical copolymerization. The influences of hydrophobic monomer content on the molecular weight, insoluble fraction and dissolution rate of PAM were investigated. The flocculation effects of PAMs for two kinds of tailing slurry with difficult sedimentation feature were also evaluated. The results show that different flocculation effects of hydrophobically modified PAMs can be obtained according to different kinds of tailing slurry.

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

2011 ◽  
Vol 50 (15) ◽  
pp. 9116-9122 ◽  
Author(s):  
Odinei H. Gonçalves ◽  
André L. Nogueira ◽  
Pedro H. H. Araújo ◽  
Ricardo A. F. Machado
Keyword(s):  
Particle Size ◽  
Methyl Methacrylate ◽  
Suspension Polymerization ◽  
Size Distributions ◽  
Operational Parameters ◽  
Particle Size Distributions

Advances in the Characterization of Particle Size Distributions of Abrasive Particles used in CMP

2007 ◽  
Vol 991 ◽  
Author(s):  
Mungai Kamiti ◽  
Stacey Popadowski ◽  
Edward E. Remsen
Keyword(s):  
Particle Size ◽  
Colloidal Silica ◽  
Particle Diameter ◽  
Water Soluble ◽  
Size Distributions ◽  
Organic Additives ◽  
Particle Size Distributions ◽  
Abrasive Particles ◽  
Theoretical Simulations

ABSTRACTThe use of density gradient stabilized centrifugal sedimentation (disc centrifugation) for the characterization of abrasive particles in CMP slurries is reported. For slurries prepared with ceria and colloidal silica abrasives, the technique is demonstrated as capable of providing highly repeatable analyses of the abrasive's apparent particle size distribution (PSD). The addition of water soluble organic additives to the slurries is shown to produce large shifts in the apparent PSD relative to the PSD of the pure abrasive particles. Particle-additive interactions driving the shift in apparent PSD could not be interpreted with confidence due to the lack of accurate densities for particle-abrasive complexes formed in the slurry. To address this problem, sucrose density gradients prepared using H2O and D2O were tested as spin fluids of different densities to analyze a colloidal silica standard with a narrow PSD. Preliminary results comparing experimental disc centrifuge data with theoretical simulations of the disc sedimentation pattern suggest that this technique can potentially characterize both the particle diameter and density of abrasive particles in a CMP slurry.

scholarly journals Modeling of the Free Radical Copolymerization Kinetics of n-Butyl Acrylate, Methyl Methacrylate and 2-Ethylhexyl Acrylate Using PREDICI®

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 395 ◽  
Author(s):  
Javier A. Gómez-Reguera ◽  
Eduardo Vivaldo-Lima ◽  
Vida A. Gabriel ◽  
Marc A. Dubé
Keyword(s):  
Free Radical ◽  
Methyl Methacrylate ◽  
Butyl Acrylate ◽  
Radical Copolymerization ◽  
Free Radical Copolymerization ◽  
Diffusion Controlled ◽  
Wide Range ◽  
Kinetics Of ◽  
Global Parameters ◽  
Copolymerization Kinetics

Kinetic modeling of the bulk free radical copolymerizations of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (EHA); methyl methacrylate (MMA) and EHA; as well as BA, MMA and EHA was performed using the software PREDICI®. Predicted results of conversion versus time, composition versus conversion, and molecular weight development are compared against experimental data at different feed compositions. Diffusion-controlled effects and backbiting for BA were incorporated into the model as they proved to be significant in these polymerizations. The set of estimated global parameters allows one to assess the performance of these copolymerization systems over a wide range of monomer compositions.

Sign in / Sign up

Export Citation Format

Share Document