scholarly journals Effect of the operating conditions on the particle size distribution by the suspension polymerization process

2019 ◽  
pp. 1-12
Author(s):  
José Josué Rodríguez-Pizano ◽  
Laura Edith Granados-Rivera ◽  
Héctor Hernández-Escoto ◽  
David Contreras-López
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Free Radical ◽  
Suspension Polymerization ◽  
Agitation Speed ◽  
Operating Conditions ◽  
Polymerization Process ◽  
Dispersing Agent ◽  
Suspension Process ◽  
Reaction Performance

In this research, we focus on the study of the operating conditions that influence on suspension process for obtaining (co)polymers of styrene with polar monomers (copolymers of styrene with acrylate of butyl (S-BA) and copolymers of styrene with vinyl acetate (S-VAc)) using the technique of conventional free radical polymerization (FRP). At higher agitation speed, the reaction performance decreases. Likewise, the influence of the molecular weight of the dispersing agent, in this case polyvinyl alcohol (PVA), influences the polymerization performance was also observed. That is, at a higher molecular weight of PVAs, there is an increase in the particle size of the bead and in the polymerization yield. Finally, there is an influence of the polar part on the copolymer both for the yield and for the particle size of the bead. When obtaining copolymers of S-VAc, the yield is lower compared to the respective styrene homopolymer and higher in the S-BA.

Synthesis of Ultra-High Molecular Weight Polyacrylonitrile (UHMWPAN) by Aqueous Suspension Polymerization

2015 ◽  
Vol 1120-1121 ◽  
pp. 615-619
Author(s):  
Hui Yu Jiang ◽  
Mei Hua Zhou ◽  
Ding Pan
Keyword(s):  
Molecular Weight ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Average Molecular Weight ◽  
Monomer Concentration ◽  
Polymerization Process ◽  
Polymerization Temperature ◽  
Different Temperatures ◽  
Total Monomer Concentration ◽  
Ultra High Molecular Weight

Acrylonitrile (AN) and itaconic acid (IA) were used to synthesize UHMWPAN by aqueous suspension method with 2,2’-azobisisobutyronitrile (AIBN) as the initiator and polyvinylalcohol (PVA) as the disperser at different temperatures (55°C~75°C) for different timings (1.0h~3.0h). The usage amounts of AN, IA, AIBN and PVA were also technical polymerization parameters used to obtain the optimal polymerization process. We found that the conversion and the viscosity average molecular weight both achieved the optimum levels when the conditions were as follows: the total monomer concentration (21wt%), the monomer ratio (AN: IA=98:2), the usage amount of the initiator (AIBN, 0.01wt%), the usage amount of the disperser (PVA, 0.1wt%), the polymerization temperature (70°C) and the polymerization time (2h).

Preparation and Characterization of Magnetic Toner Particles by Direct Polymerization Method

2011 ◽  
Vol 217-218 ◽  
pp. 1702-1707
Author(s):  
Yu Feng Duan ◽  
Zhao Xia Fu
Keyword(s):  
Particle Size ◽  
Glass Transition ◽  
Influence Factor ◽  
Suspension Polymerization ◽  
Spherical Surface ◽  
Crosslinking Agent ◽  
Polymerization Process ◽  
Stirrer Speed ◽  
Sem Image ◽  
Polymerization Method

In this study a kind of black toner, containing polymer, magnetic iron oxide pigment, and several other additives, was prepared by a suspension polymerization method. The morphology, influence factor of particle size, and glass transition of prepared toner were discussed. SEM image showed that the produced micron-sized particles have a spherical surface and the various chemicals were mixed into monomers during manufacturing of the particles. Discussion about particle formation and stability concluded that the toner particle size related with stabilizer concentration, stirrer speed, and crosslinking agent concentration. The bigger particles, resulted from droplets coalescence during polymerization process, disappeared when enough PVA stabilizer was used in the aqueous medium. .Increasing the stirrer speed corresponded to the decrease of the particles size. But any increase in stirrer speed t did not contribute to size reduction in small particles below 2μm. It was found that particle size decrease with the addition of crosslinking agent. The DSC result indicated the glass transition of polymerized toner could be effectively adjusted according to Fox equation through change the monomer ratio.

scholarly journals Manufacture of poly(methyl methacrylate) microspheres using membrane emulsification

2016 ◽  
Vol 374 (2072) ◽  
pp. 20150134 ◽  
Author(s):  
Jaiyana Bux ◽  
Mohamed S. Manga ◽  
Timothy N. Hunter ◽  
Simon Biggs
Keyword(s):  
Methyl Methacrylate ◽  
Suspension Polymerization ◽  
Cross Flow ◽  
Good Control ◽  
Close Correlation ◽  
Operating Conditions ◽  
Polymerization Process ◽  
Polymer Particles ◽  
Membrane Emulsification ◽  
Poly Methyl Methacrylate

Accurate control of particle size at relatively narrow polydispersity remains a key challenge in the production of synthetic polymer particles at scale. A cross-flow membrane emulsification (XME) technique was used here in the preparation of poly(methyl methacrylate) microspheres at a 1–10 l h −1 scale, to demonstrate its application for such a manufacturing challenge. XME technology has previously been shown to provide good control over emulsion droplet sizes with careful choice of the operating conditions. We demonstrate here that, for an appropriate formulation, equivalent control can be gained for a precursor emulsion in a batch suspension polymerization process. We report here the influence of key parameters on the emulsification process; we also demonstrate the close correlation in size between the precursor emulsion and the final polymer particles. Two types of polymer particle were produced in this work: a solid microsphere and an oil-filled matrix microcapsule. This article is part of the themed issue ‘Soft interfacial materials: from fundamentals to formulation’.

Narrow molecular weight resins by a free-radical polymerization process

1993 ◽  
Vol 26 (11) ◽  
pp. 2987-2988 ◽  
Author(s):  
Michael K. Georges ◽  
Richard P. N. Veregin ◽  
Peter M. Kazmaier ◽  
Gordon K. Hamer
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Radical Polymerization ◽  
Free Radical Polymerization ◽  
Polymerization Process
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