Addition - Fragmentation type initiators for cationic polymerization


Yagci Y. , REETZ I.

MACROMOLECULAR SYMPOSIA, cilt.132, ss.153-164, 1998 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 132
  • Basım Tarihi: 1998
  • Dergi Adı: MACROMOLECULAR SYMPOSIA
  • Sayfa Sayıları: ss.153-164

Özet

Addition - fragmentation reactions are a versatile and exceptionally interesting tool in preparative polymer chemistry. With the aid of specially designed allyl-onium salts (addition - fragmentation agent, AFA) in conjunction with conventional radical initiators it is possible to very efficiently initiate cationic polymerizations. The mechanism involves (a) the formation of radicals by heating or irradiating the radical initiator, (b) the addition of these radicals to an AFA molecule and (c) the fragmentation of the AFA. In step (c) radical cations are produced, which with high rates initiate the polymerization of cationically polymerizable monomers (e.g., cyclohexene oxide, CHO). In order to show good performance in initiation reactions, AFAs have to be equipped with functional groups or substituents which either promote radical addition or facilitate the fragmentation of reaction intermediates.