Addition-Fragmentation Reactions for Cationic Polymerization using a Novel Allyloxy-picolinium Salt

Abstract

A novel allyloxy‐picolinium salt, N‐[2‐(methyl)allyloxy]‐α‐picolinium hexafluoroantimonate, has been synthesized and used as addition–fragmentation agent for radical promoted thermal and photochemical cationic polymerization of monomers such as cyclohexene oxide, p‐methoxystyrene and various vinyl ethers. Polymerization by heat was achieved using the allylic salt in conjunction with benzoyl peroxide (BPO), phenylazotriphenylmethane (PAT) and 2‐2′‐azobis‐isobutyronitrile (AIBN). Polymerization rates were found to drop in the order PAT>BPO>AIBN. Photopolymerization was carried out by irradiating the allyloxy‐picolinium salt in the presence of monomer at 280nm. Upon adding benzoin as free radical source, the spectral response was extended to 370nm. The initiation mechanism is explained in terms of an addition–fragmentation scheme. © 1997 SCI.

A Novel Bifunctional Addition-Fragmentation Agent for Photoinitiated Cationic Polymerization

“…[3] Among these, recently developed allyl-onium salts, [4][5][6][7][8][9][10][11][12][13] which initiate via addition-fragmentation mechanism, are a promising novelty (see Scheme 2).…”

Initiation of Cationic Polymerization by Using Allyl Anilinium Salts in the Presence of Free Radical Initiators

“…Recently various types of allylonium salts have been synthesized and employed together with free radical sources in the cationic polymerization. [6][7][8][9][10][11][12][13][14][15][16] The mechanism of the initiation consistent with previous studies, is explained in terms of radical addition fragmentation. In this study, allylanilinium salts having different substituents on the allylic double bond are employed in the presence of various radical sources in the polymerization of CHO.…”

“…[6][7][8][9][10][11][12][13][14][15][16] The intermediate radical cation, formed by the addition of the thermally or photochemically generated radical on the allylic salt, undergoes fragmentation, producing another radical cation which is capable of initiating cationic polymerization as illustrated on the example of allyl thiophenium salts (Scheme 1).…”

Control of reactions and network structures of epoxy thermosets

“…65. Allylsulfonium salts [353], allylpyridinium salts [354], allyloxypyridinium salts [355][356][357], allylanilinium [358] salts and allylphosphonium salts [295] were synthesized and successfully used in combination with thermal radical initiators to polymerize a variety of epoxy monomers. The numerous radical initiators, including AIBN or benzoyl peroxide (BPO), offer flexibility to this initiation strategy.…”