vaiheenpolimerisaatiot

Vaiheenpolimerisaatiot, or phase polymerization in English, refers to a type of polymerization reaction that occurs at the interface between two immiscible phases. In this process, monomers are present in one phase, while the initiator or catalyst is in the other. The polymerization is initiated at the interface and proceeds into the monomer-containing phase. This method is particularly useful for producing polymers with controlled molecular weights and narrow molecular weight distributions.

There are several variations of phase polymerization, including suspension polymerization, emulsion polymerization, and inverse emulsion polymerization. In suspension polymerization, monomer droplets are dispersed in a continuous aqueous phase, and a monomer-soluble initiator is used. Emulsion polymerization involves the formation of micelles in an aqueous phase where the polymerization takes place, with a water-soluble initiator. Inverse emulsion polymerization is similar but uses a water-in-oil system.

Phase polymerization offers advantages such as efficient heat removal due to the continuous phase, which can be a liquid, and the ability to produce polymers in a form that is easily handled, like beads or latexes. The morphology of the resulting polymer particles can be influenced by factors such as stirring rate, surfactant concentration, and the nature of the monomer and initiator. This technique finds applications in the production of various polymers, including polyvinyl chloride, polystyrene, and acrylic polymers, used in coatings, adhesives, and plastics.