addition polymerization

(redirected from Addition polymerisation)
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addition polymerization

[ə¦dish·ən pə‚lim·ə·rə′zā·shən]

(organic chemistry)

A reaction initiated by an anion, cation, or radical in which a large number of monomer units are added rapidly (a chain reaction) until terminated by some mechanism, forming a high-molecular-weight polymer in a very short time; an example is the free-radical polymerization of propylene to polypropylene.

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vinyl polymerization

References in periodicals archive ?

The catalyst paste contains vinyl-terminated poly (dimethylsiloxane) and a catalyst such as chloroplatinic acid.8,10-12 The fillers, such as amorphous silica or fluorocarbons, are added to both the pastes to improve mechanical properties.7,10 The VPS impression materials are presented in different viscosities; extra light-bodied, light-bodied, medium-bodied, heavy-bodied and putty.8,10,13 When the two pastes are mixed, an addition polymerisation reaction occurs forming a cross-linked molecules in the set state.7,12,14,15

SETTING CHARACTERISTICS OF THREE COMMERCIAL VINYL POLYSILOXANE IMPRESSION MATERIALS MEASURED BY AN OSCILLATING RHEOMETER