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cationic polymerizationZoomA-Z

Subject - Macromolecular Chemistry

Cationic polymerization is one of the variants of different polymerization reactions. This reaction proceeds by frequently repeated additions of monomers with sufficiently high nucleophilicity to a positively charged, electrophilic chain terminus. The growing macrocations can be carbocations or oxonium ions. In general, three types of monomers can undergo cationic polymerization:

  1. electron-rich olefin derivatives containing electron donating substituents R;
  2. heteronuclear multiple bonds with heteroatoms or heterogroups Z; and
  3. rings containing heteroatoms Z, e.g. O, S, N, P.

Suitable initiators are Brønsted acids (perchloro-, trifluoromethanesulfonic acid), Lewis acids (boron trifluoride, aluminum trifluoride; if necessary together with water or hydrogen chloride) or combinations of (ar)alkylhalogenides with Lewis acids.

See also: ionic polymerization