Stabilizer for dispersion polymerization,

The dispersion polymerization system is composed of monomer, solvent, initiator, and stabilizer. The combination of monomer, solvent, and stabilizer is essential for particle preparation. That is to say, the stabilizer is chosen to meet the demand of the monomer and solvent. In any system, the stabilizer has affinity or cohesive strength for both the medium and the polymer particles. In a dispersion polymerization, the medium and polymer particles both are organic compounds. Therefore, it is not rational to rely on dispersion stabilization, which comes from the electrostatic repulsion force between particles. The stabilizer for dispersion polymerization that makes interfacial energy low must have affinity for particles due to the same quality and solvation at the surface of particles. It is desired that the stabilizer be a polymer that indicates a steric stabilization effect on the surface (5). 

From a similar idea based on the surface area stabilized by a stabilizer, a presumption equation could also be made for dispersion polymerization that uses macromonomer, a precursor stabilizer, which has a pendant group as a solvating component (14). 

The minimum requirements for a dispersion polymerization are monomer, solvent/nonsolvent, initiator, and steric stabilizer. The monomer must be soluble in the reaction mixture and its polymer, insoluble. The monomers used in systems of commercial interest are methyl methacrylate, vinyl chloride, vinyli-dene chloride, vinyl esters, hydroxyl alkyl acrylates. A typical recipe for dispersion polymerization is shown in Table 9. 

Dresinate . [Hercules Hercules BV] Rosin so emulsifier, pigment wetting agent, dispersant, foaming agent, stabilizer for adhesives, polymerization, metalworiting, drilling muds, asphalt, industrial and househdd ctean-ers. 

Gafac . [Rhone-Poulenc Surf.] Phosphate esters emulsifier for pesticides industrial and household detergent emulsifier and stabilizer for emulsion polymerization solubilizer, hydro-trope textile antistat, lubricant, softener, dispersant, wetting agent cosmetics ingredient. 

Lomar . [Henkel/Emery Henkel-Nopco] NafAdialene sulfonate condensates emulsifier, leveling agent, dispersant suspending agent stabilizer for emulsion polymerization, dyestuff mfg., ceramics, paint paper, rubber, agric. formulations. 

Polystep . [Stepan SmpanEunH>e] Sulfonates, sulfates, or nonoxynols emulsifier, surfactant, dispersant, stabilizer for entulsion polymerization, floor polishes, coatings. 

FizuL [Finetex] Sulfosuccinatesorsulfo-succinamates emulsifier, wetting agent dispersant emulsifier, solubilizer, stabilizer for emulsion polymerization, foaming wallboards, floor polishes, shanqtoos. 

Geropon . [Rhone-Poulenc Surf. Rhone-Poulenc Geronazzo SpA] Sul-fosuccinates, sulfosuccinamates, tau-rates, isethionates, or sulfonated polyester emulsifier, wetting agent, suspending agent, dispersant, stabilizer for emulsion polymerization, pesticides, inks, textiles, paints. 

Block and Graft Copolymer Stabilizers in Dispersion Polymerization. A sterically-stabilized, nonaqueous, polymer dispersion is made simply by heating a solution of a free radical initiator (e.g., azobisisobutyronitrile), an appropriate monomer, and a suitable block or graft copolymer in an organic liquid which is a nonsolvent for the polymer product and acts as a diluent for the dispersion. The block or graft copoly-... 

Both polar and non-polar solvents may be used for dispersion polymerization. Whilst the earlier woric on dispersion pofymerization involved the use of petroleum distillates and other alii iatic hydrocarbons, most of the recent studies have used polar solvents such as etiianol and methanol [11,12]. There are few examples of true, radically initiated dispersion polymerizations in which water is tire sole solvent. In many cases using alcohol solvents, water is added in order to fine tune the solvency and thus manipulate the particle size, and size distribution, of the product. Some of the earlier reports on dispersion polymerization in aqueous media were strictly suspension polymnizations. In one of the few true examples of an aqueous system, Margel and l esel [13] polymerized acrolein in water in the presence of a polyglutaraldehyde stabilizer, using eith base... 

Uses Emulsifier, dispersant, stabilizer for latex polymerization, agric.. latex paints, iodophors, dye pigments, leather finishes emulsifier for silicone oils... 

Uses Emulsion polymerization surfactant stabilizer for dispersions pigment dispersant... 

Salt derivatives for emulsion polymerizations Salt stabilizers for emulsion polymerizations Synthetic resin dispersant agent... 

A silicone macromonomer has also been used to stabilize the dispersion polymerization of PMMA (44). The PDMS macromonomer used in this study was a commercially available methacryloxy functional PDMS macromonomer (Fig. 9). The polymerizations were carried out at 340 bar and 65 C for 4 h. When no PDMS macromonomer was added to the polymerization, only low conversions could be achieved and the polymer precipitated. Addition of a small amount of PDMS macromonomer (0.05 wt %) to the polymerizations increased the molecular weight and the yield of the polymer, but at least 3.5 wt % was necessary to obtain monodispersed polymer particles at high yield. PDMS homopolymer, which lacks the reactive MMA functional group, was not effective in stabilizing the polymerization in that a much greater concentration of the... 

Uses Pigment dispersant in aq. media, for low color disps., agric. chemicals, mastics, caulks, sealants, pigment slurries and disps., textiles reduces water and/or viscosities of dispersions and suspensions stabilizer for emulsion polymerizations wetting agent for carbon bik. settling inhibitor for agric. chems. water reducer for metal oxides... 

Uses Emuisifier for cosmetics, pharmaceuticals, agric. emulsifier, dispersant, solubilizer for oils stabilizer for emulsion polymerization Features Highly hydrophilic... 

Uses Surfactant, wetting agent, emulsifier, dispersant emulsion stabilizer for emulsion polymerization... 

Uses Dispersant for low color applies., calcium sensitive systems, pigment dispersions stabilizer for emulsion polymerization water reducer for metal oxides, specialty dispersions... 

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