Allyl Sulfonium Salt as a Novel Initiator for Active Cationic Polymerization of Epoxide by Shooting with Radicals Species

作者：Yilmaz Faruk; Sudo Atsushi; Endo Takeshi^*

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2010, 48(19): 4178-4183.

DOI：10.1002/pola.24198

• addition-fragmentation reactions
• allylic sulfonium salt
• radically triggered cationic polymerization
• redox system

A rapid cationic polymerization of cyclohexene oxide that completed within a few minutes was achieved by a new initiation system that involves (1) a copper-catalyzed reduction of benzoyl peroxide by an ascorbic acid derivative that generates free radicals and (2) capture of the radicals by allyl sulfonium salt having hexafluoroantimonate (SbF(6)(-)) as a counter anion, followed by fragmentation of sulfonium radical cation, from which a super acid HSbF(6) was produced to initiate the rapid polymerization. The key factor in designing an efficient allyl sulfonium salt was attachment of an electron withdrawing ester group at the allyl group, of which ability to stabilize the formed radical can enhance the efficiency in trapping radicals by the allylic salt.

• 出版日期2010-10-1