Importance of Cationic Polymerizations

Polymers produced by cationic vinyl polymerizations include poly(A/-vinylcarbazole) and poly(vinyl ether). However, polyisobutylene and its copolymer with isoprene (butyl rubber) is probably the most important commercial polymer produced by a cationic polymerization. Other industrial polymers such as poly(styrene) can be prepared by cationic polymerization, although they are usually produced radically or anionically. Many low molecular weight polymers produced by cationic polymerizations of 

Allcock and F. W. Lampe, Contemporary Polymer Chemistry, Prentice-Hall., Englewood Cliffs, New Jersey, 1990. 

Rempp and E. W. Merrill, Polymer Synthesis, Huthig Wepf Verlag, Basel, 1991. 

Stevens, Polymer Chemistry. An Introduction, Oxford University Press, New York, 1990. 

Allen and J. C. Bevington, Comprehensive Polymer Science, Pergamon Press, Oxford, 1989. 

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Cationic Poiymerization. Like anionic pol5unerization, cationic polymerization is an addition reaction involving a relatively stable ionic propagating species. Cationic polymerization proceeds by an attack on the monomer by an electrophilic species, resulting in heterolytic cleavage of a double bond producing a carbocation. In the case of olefins, the carbocation is of the carbenium form. The most complete reference to date acknowledging the importance of cationic polymerization chemistry is a 1975 book (360). 

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