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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.
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation.Emulsions are part of a more general class of two-phase systems of matter called colloids.
A miniemulsion (also known as nanoemulsion) is a particular type of emulsion.A miniemulsion is obtained by ultrasonicating a mixture comprising two immiscible liquid phases (for example, oil and water), one or more surfactants and, possibly, one or more co-surfactants (typical examples are hexadecane or cetyl alcohol).
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.
Although they are attracted to oil, and an oil-in-water emulsion forms, the emulsion will not stay stable for long and will eventually coalesce. [10] With the addition of a polyelectrolyte, electrostatic forces between the oil and water interface are formed and the surfactant begins to act as an “anchor” for the polyelectrolyte, stabilizing ...
All polymerization occurs in the continuous phase, rather than on both sides of the interface between the continuous phase and the core material. In situ polymerization of such formaldehyde systems usually involves the emulsification of an oil-phase in water. Then, water-soluble urea/melamine formaldehyde resin monomers are added, which are ...
Preparation of block copolymers by iodine-transfer polymerization was also described by Tatemoto and coworkers in the 1970s. [15] Although use of living free radical processes in emulsion polymerization has been characterized as difficult, [16] all examples of iodine-transfer polymerization have involved emulsion polymerization. Extremely high ...