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In polymer chemistry, emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomers, and surfactants.The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer (the oil) are emulsified (with surfactants) in a continuous phase of water.
For example, for the polymerization of ethylene, 93.6 kJ of energy are released per mole of monomer. [8] The manner in which polymerization is conducted is a highly evolved technology. Methods include emulsion polymerization, solution polymerization, suspension polymerization, and precipitation polymerization.
Mini-emulsion: emulsion in which the particles of the dispersed phase have diameters in the range from approximately 50 nm to 1 μm. Note 1 : Mini-emulsions are usually stabilized against diffusion degradation (Ostwald ripening (ref. [ 6 ] )) by a compound insoluble in the continuous phase .
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation.
Suspension polymerization is divided into two main types, depending on the morphology of the particles that result. In bead polymerization, the polymer is soluble in its monomer and the result is a smooth, translucent bead. In powder polymerization, the polymer is not soluble in its monomer and the resultant bead will be porous and irregular. [5]
The kinetics of microemulsion polymerization has much in common with emulsion polymerization kinetics, the most characteristic feature of which is the compartmentalization, where the radicals growing inside the particles are separated from each other, thus suppressing termination to a high extent and, as a consequence, providing high rates of ...
Dispersion polymerization can produce nearly monodisperse polymer particles of 0.1–15 micrometers (μm). This is important because it fills the gap between particle size generated by conventional emulsion polymerization (0.006–0.7 μm) in batch process and that of suspension polymerization (50–1000 μm). [4]
In emulsion polymerization, starve-fed refers to a method of monomer addition where the monomer is introduced gradually into the reaction vessel at a rate that allows the majority of monomer to be consumed by the reaction before more is added.