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Anionic Polymerization of Olefins

المؤلف:  A. Ravve

المصدر:  Principles of Polymer Chemistry

الجزء والصفحة:  182

2026-01-18

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Anionic Polymerization of Olefins

As is stated in the beginning of this chapter, the distinctive features of the anionic chain-growth polymerizations are the negative charges at the active centers. Many different bases initiate such polymerizations, depending on the monomer. The most common ones are organometallic compounds, alkali metals, metal amides, and Grignard reagents. Monomers with carbanion stabilizing substituents, either through resonance or through induction, polymerize most readily. Such substituents, in fact, determine the base strength of the initiators needed to carry out these polymerizations by their electron withdrawing capacity. Thus, for instance, very weak bases, such as water, initiate vinylidene cyanide polymerizations:

Potassium bicarbonate initiates polymerization of 2-nitropropene:

On the other hand, monomers like acrylic or methacrylic esters and conjugated dienes require strong bases, like alkali metals or organometallic compounds.