Catalysis of cationic polymerization

Attempts to bring the benefits of ionic Hquid technology, drawing on this inherent ability of the chloroaluminate(lll) ionic liquids, to catalysis of cationic polymerization reactions, as opposed to their minimization, were patented by Ambler et al. of BP Chemicals Ltd. in 1993 [29]. They used acidic [EMlM][Cl-AlCl3] (X(AlCl3) =... 

A detailed study of mechanisms both of photodecomposition of triarylsul-fonium salts to yield Bronsted acids and of catalysis of cationic polymerization of representative monomers—styrene oxide, cyclohexene oxide, tetrahydrofuran (THF), and 2-chloroethyl vinyl ether—was reported in 1979 by Crivello and Lam [14]. Crivello [15] and Green et al. [16] provided further reviews shortly thereafter. The mechanisms of photodecomposition of a variety of initiators for free radical photopolymerization, including onium salts, were compared by Vesley [17] in 1986. A review, similar in scope, but providing more mechanistic detail was also published in 1986 by Timpe [10a]. An updated coverage of aspects of this chemistry has been provided by the same author in his review of photoinduced electron transfer polymerization [10b]. 

Catalysis of cationic polymerization requires formation of Bronsted acid, while the product of interest in connection with free radical cures is an aryl radical. Early results [69] suggested that the photogeneration of acid, followed by an indicator technique, might be more efficient than formation of the radical products, estimated as Phi and Ph2S, for photolysis of Ph2I+ and... 

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